Re: [AMRadio] Breaker Info
There are so many What if's that only guessing works well. There are also Shunt Trip breakers that break with say 50 mills to cut a 20 amp circuit. Usually we think of a breaker with a bi-metal strip heating and curling out of the way at a certain temp caused by over current. Some even reset by themselves!. The shut trip can be configured to trip if a overvoltage condition occurs instead of over current. Even if a interlock door is opened. I have a Heinemann that has extra coils that sense the current while the contacts only open or close the circuit without regard to actual current through contacts.Think it is called hydraulic, but I would bet there is no oil.. Just another $0.01 worthless.. 73 Mike Bi-metal is very interesting stuff. Since all metals have a different thermal coefficient of expansion, two metals of different types bonded together will curl when it gets hot or cold.Makes dandy breakers, and thermostats! - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 04, 2006 12:40 PM Subject: Re: [AMRadio] Breaker Info On Mon, 4 Dec 2006, Jack Schmidling wrote: I need some help understanding the main power switch on my powersupply. Here is some info on current (no pun intended) Hienemann/Eaton brakers - http://www.circuitbreakersinc.com/cirguide.pdf it's possible you have one of the dual-rating devices - with two different ranges that will trip the breaker. The diagrams show 38 different configs - a bit more tracing and/or voltmeter work might narrow this down some. Cheers John KB6SCO DM90fg __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Meter
the meter you describe is from a Johnson 6 and 2. It would need no repair. it looked neat in the 6N2 mounted up side down. - Original Message - From: Rick Brashear [EMAIL PROTECTED] To: AMRadio@mailman.qth.net Sent: Friday, November 24, 2006 11:31 PM Subject: [AMRadio] Meter I am in search of info on a meter. The one I have is out of a Ranger and it works backwards! I don't know if somewhere down the line it was zapped or what, but it works fine and is accurate as far as I can tell, however, it works from right to left instead of left to right. The scale is correct for a normal reading meter so I know it wasn't made that way. The needle rests on the right side of the meter. It is an original Johnson Ranger meter. Has anyone ever encountered such a thing? Does anyone do meter repair? Thanks, Rick/K5IZ __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] Changes to band plan EST
The changes in the RO will take effect Friday, December 15, at 12:01 AM EST, 30 days after its publication. __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger Audio... the numbers
Audio transformers are rated for impedance step up or down. It is ,of course, the square of the turns ratio. A simple check is a known voltage at 1 khz, say 1 volt, and read the voltages of the windings. The z can be determined by applying a ac voltage at a frequency of interest and placing a resistor in series with the winding and adjusting the resistance until the same voltage is on both. The resistive value is equal to the z of the winding. The peak voltage, RMS times 1.414 must equal the B plus, in this case 550 volts or so in order to modulate 100 percent. Also, even thougth a 1614 is a healthy 6l6 a 6l6 is not a 1614. One (the 6L6) is rated by any manufacturer at 360 volts MAX and the 1614 is 550 volts, hey, the same as the Ranger Power supply, Imagine that! Also lest we forget the modulating load is the B plus divided by the current. The RF tube load impedance is the Voltage divided by TWICE the current. The tank values and operating Q depends on operating at the designed value. Ditto the load the modulator sees. On z's of windings the transformer need not operate at the stated z, as long as the ratios are correct. Too low of frequencies would not have enough iron and too high would make it jump through the capacity instead of the iron. But a 2 to 1 at say 6000 to 3000 ohms would work fine a 12000 and 6000 ohms..or 3000 to 1500 ohms. Transformers for light commercial service and amateur service are rated for a certain amount of DC in the windings, these can not be exceeded or the thing will become a magnet and not work. Saturation, I think they call it! Hope this hepls a little. 73 Mike - Original Message - From: Jack Schmidling [EMAIL PROTECTED] To: Mike Dorworth, K4XM [EMAIL PROTECTED]; Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Saturday, November 18, 2006 10:14 AM Subject: Re: [AMRadio] Ranger Audio... the numbers Mike Dorworth, K4XM wrote: Ranger modulation Transformer 33 watts voice Primary 7083.8 ohms plate to plate. Red is ct. Secondary 3571 ohms. Black is ct. 892 ohms each side to tridode grids. You lost me here. The manual says 100 ohms and 28 ohms respectively 1.9837 Z stepdown ( nominal 2:1) 1.4085 step down turns ratio.. I guess we are talking z vs resistance. So, how does one measure the Z of a transformer? If I put a 1khz sig in one end should the amplitude drop by the z stepdown ratio? js __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger Audio... the numbers
- Original Message - From: crawfish [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Friday, November 17, 2006 7:54 PM Subject: Re: [AMRadio] Ranger Audio... the numbers Impedance at the plates is more than 50 ohms. Some measurements: Ranger modulation Transformer 33 watts voice Primary 7083.8 ohms plate to plate. Red is ct. Secondary 3571 ohms. Black is ct. 892 ohms each side to tridode grids. 1.9837 Z stepdown ( nominal 2:1) 1.4085 step down turns ratio.. hope this helps someone.. mike __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] 220 volt AC Power Question
Jim I do not know the laws but all new dryers have four wire cords. Only the old ones are three. The ground wire would need to be twice as big as either hot wire. By the codes I don't think you can use a neutral for fault current. At the box, the neutral and ground are tied together. Most stoves and dryers are 220 and the third wire is for the fuse blowing function only but there must be exceptions. Hope the electricians let you know exactly. 73 Mike - Original Message - From: Jim candela [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, October 30, 2006 8:09 PM Subject: [AMRadio] 220 volt AC Power Question Hi all, I am building an amplifier that has a combination of 220 volt and 120 volt transformers. The HV plate supply is 220V, and the rest is 120V. I will be keying the plate supply. My 220V outlet has phase, phase, and ground. There is NO neutral. The outlet is not a GFCI outlet so ground current will work, BUT. The BUT here is whether this is legal with the National Electric Code? Before you say NO, consider the electric clothes dryer. These all run off 220V, and have 3 prong power cords. I have heard that in some dryers there are 120 volt loads (lights, and timer) as well as 220V (heater and motor). If this is true, then my approach must be OK so long as my power switch uses a DPST switch and (double fuses)to insure everything is off when it is in the OFF position. Comments please... BTW, I do have a 240/120 autotransformer of suitable size (VA rating), but space does not permit it's use. Jim JKO -- No virus found in this outgoing message. Checked by AVG Free Edition. __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] 6L6 or 1614
A 6L6 in any book is listed at 360 volts Maximum. The 1614 is listed at 550 volts ICAS and, of course, the unmodified Ranger uses 550 Volts DC on the final and modulator. We once had a post that the 1614 is really only a selected for high voltage service 6L6 and it sounds reasonable to me. In fact, the 1614 is listed as a RF Transmitting tube in the RCA Transmitting tube manuals but, alas, the 6l6 is not. Use what you got. 73 Mike - Original Message - From: Rick Brashear [EMAIL PROTECTED] To: AMRadio@mailman.qth.net Sent: Friday, October 27, 2006 3:32 PM Subject: [AMRadio] 6L6 or 1614 Both will work in a Johnson Ranger and no doubt the 1614 is the better choice, but does anyone have facts as to the feasibility of using the 6L6? I personally think the 6L6 works fine, but doesn't last long in comparison. Any thoughts? Thanks, Rick/K5IZ __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] 6L6 or 1614
Let me add that a 6L6GC is rated at higher voltage and I suppose the 5881 military 6L6 is rated for more volts and would make a dandy substitue for the 1614.. 73 Mike - Original Message - From: uvcm inc. [EMAIL PROTECTED] To: 'Discussion of AM Radio in the Amateur Service' amradio@mailman.qth.net Sent: Friday, October 27, 2006 3:37 PM Subject: RE: [AMRadio] 6L6 or 1614 Both will work in a Johnson Ranger and no doubt the 1614 is the better choice, but does anyone have facts as to the feasibility of using the 6L6? I personally think the 6L6 works fine, but doesn't last long in comparison. Any thoughts? Thanks, Rick/K5IZ Try 6550 or KT88 used them for over 20 years never damaged or harmed any component on a ranger 1 Brad Kb7fqr __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Microphone assistance
The trouble with low z microphones is that some times Once a Hi-Z mike sends it's signal out it needs a short low capacity cable to keep from effectively shorting the highs. Putting a transformer in the mike is ok as long as the cord is low capacity and short. The 9 foot cord sounds like a disaster waiting to happen. The reason, I thought, for the LowZ mics was so a long cable, 20, 30 40 50 feet would not suffer such troubles. The idea of a mixer and then the Z conversion sounds good.. Just another $0.02.. Mike __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Microphone assistance
. I was thinking of a transformer in the microphone case and the 9 foot cord which goes against my grain. I know we can make any of them work. When I hear AM radio guys talk about HighZ I think of a D-104 and it's ilk at about 5 megohms, this is high Z! When I hear 30K ohms I am thinking of a Hi-Z SSB like Kenwood TS520s,Drakes and Collins. That is what they call high Z. Most broadcast mics, I think are about 50 ohms ( dynamic types). I notice that a Shure 515SB is rated at 150 ohms, actual is 170 ohms and is for use on 19 to 300 ohm inputs..I too like the mixer plan.. 73.. Mike - Original Message - From: John E. Coleman (ARS WA5BXO) [EMAIL PROTECTED] To: 'Mike Dorworth, K4XM' [EMAIL PROTECTED]; 'Discussion of AM Radio in the Amateur Service' amradio@mailman.qth.net Sent: Thursday, August 31, 2006 5:40 PM Subject: RE: [AMRadio] Microphone assistance You are correct Mike, One way to help with the cable capacitance trouble, if a XFMR is to be used to step up the voltage, is to put the XRMR close the input circuit or preferably in the speech amp chassis and incorporate a 3 pin XLR connector. Run balanced low Z from the microphone to the XLR input and using the shield of the cable for just a shield and not common the audio of the microphone. The mixer is a good plan if available and may have other uses. __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Antenna Idea and lightning precautions
Motorola says the simple measure of placing a piece of pipe over the coax where it enters the house and bending the coax sharply where it stops it's downward run and enters the house is good. I KNOW that lightning goes in straight lines and the few thousand amps on the coax would see the pipe as a transformer with a single shorted turn that can handler thousands of amps for long enough delay time for the juice to jump to ground . To help it along. commercial installations strip the jacket off and wrap a copper strap around the coax at the bend ( JUST BEFORE) AND CONTINUE ON DOWN WITH A NUMBER 6 OR NUMBER 2 GROUND WIRE. The scrap of pipe, perhaps a foot long need not be grounded it is merely a transformer turn that can take it a very cheap insurance policy regardless of all the other really good advice and opinion to be found on the sublect! 73 Mike
Re: [AMRadio] Antenna Idea and lightning precautions
I can see this is the beginning of a long thread since everyone has their own ideas. In commercial work a sharpened spike above the thing to be protected is to DRAW the lightning to a well insulated and very well grounded ground system. This is to protect the equipment below it. To dissipate, the ball should be rounded like a car radio antenna to gently discharge the corona. We put up a series of 150 foot towers at work with a 21 foot stainless sharpened lightning spike above the tower top to draw the lightning. All of our ( 92 each) microwave towers had a 3 or four inch diameter sharpened brass rod 2 feet above the tip top of the tower. It's ground cable was insulated from the tower all the way down. Of course the tower and all the guys were also grounded to the common ground. A dipole can easily discharge static build up with a 100 k ohm resistor of at least 1 fourth watt. This keeps the system equalized. Lightning usually hit the HIGHEST ( though noy always) spot, so if there are taller trees they would get it first. I like insulated wire instead of bare since the damp wind will not build up thousands of volts when it blows over..just before a storm. For fun take the antenna connector and put in a mason jar and place near ground and watch the 4 inch long blue firs just before a storm on a hilltop. A Johnson Matchbox sounds like a fourth of July celebration if left connected. I guess, in the end a direct strike is bad news in every case. Most of us are really talking about big static discharges I think. A real strike will blow every receptacle in the house out and the wire on on side of every power cord will vaporize and the fuse box will be blown off the wall. Let the tall trees take that!.. 73 Mike - Original Message - From: Jim candela [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Saturday, August 05, 2006 2:36 PM Subject: [AMRadio] Antenna Idea and lightning precautions Hi All, I am contemplating putting up an inverted Vee antenna where the center point is above my house suspended with a 30' Lowes push up mast attached to my roof with a tripod mast base made for roof mounting. This would make the apex at almost 50', and with the trees around my home, the ends at about 30'. Other locations that I might have the antenna apex at will be densely surrounded by trees, and I am trying to avoid that. My question is about lighting concerns with this approach. I would have multiple 12 awg ground straps from the mast base to earth ground via copper ground stakes at least 5' long. This would act as a counterpoise for the antenna, and provide a DC ground reference for the 30' mast. My fear is that the antenna would attract a lightning hit (direct) and that would cause my home to burn up in a flaming fireball. Then I was thinking about how lightning rods work, and when done properly, don't lightning rods work by having a sharp point at the tip, where they bleed the static (a corona discharge) to prevent a lightning strike? If so, why can't I take a 1/8 stainless 8' whip with a point on top, mounted above the inverted Vee apex, and use that as a lightning rod? I guess I'd need to beef up my ground wiring scheme just in case of a direct hit. Any suggestions? I am hoping for having more lightning protection with my antenna in place over that of no antenna at all? Is this possible? Regards, Jim Candela WD5JKO -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.10.7/409 - Release Date: 8/4/2006 __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] DC Load
In January 1950 CQ magazine page 20 the article Licking the Regulation Problem by Joseph Saugier, Jr. W9KSQ describes a electronic bleeder resistor , the 2500 volt 400 ma version used a pair of 211 tubes.At that time 211 were the cheapest tubes in surplus. - Original Message - From: Don Merz [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, August 02, 2006 5:30 PM Subject: [AMRadio] DC Load A local ham SK built himself a variable DC load which I recently found in the N3BM estate stuff. The ham was W3QNI. QNI worked for Western Electric and was a master builder. He must have died 10 or 15 years ago. I have one of his transmitters and it is almost a work of art. This Variable DC Load is no different.
Re: [AMRadio] Re: WRL Globe King 500C rebuild
811A's take -4.5 volts bias @ 1500 volts and give about 340 watts audio level. They will take 2000 volts OK since the am rating is 1250 volts ( 2500 volts peak). 9 volts is the standard for 2000 volts I think.The Viking 500 uses 811A at 2000 volt and OK by the tube manufacturer at that time. Since the 572B is a 2750 volt tube and will give way over 500 watts audio I would just use them since the transformer is adjustable and going to changed anyway. That way the voltages can all be the same.Mod and final. 73, Mike
[AMRadio] Radio Handbook
The latest and LAST is the 23rd edition. (1987) Bill Orr is SK. Try E-Pay.. - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Friday, June 09, 2006 7:07 AM Subject: [AMRadio] Radio Handbook I am looking for a recient copy of the Radio Handbook anyone know where I can find one? I think the latest edition is the 21st. ed. 73, Steve ve2swc
Re: [AMRadio] PA set up using ant analyzer
- Original Message - From: Edward B Richards [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, June 08, 2006 5:48 PM Subject: Re: [AMRadio] PA set up using ant analyzer Hi Dennis; I am having trouble resonating the plate tank on the linear amplifier I just built. When checking for resonance with a grid dip meter using a 5,000 ohm resistor from plate to ground, should the tubes (4-400 X 2) be in the circuit? This is not Dennis but the answer is the tubes must be there or a capacitor equal to the total output capacity of the tubes in their place. i.e.28 pf ( 14 each) for a pair of 813's check tube table for output cap. The analyzer should show a 1 to 1 swr from the antenna looking in when it is resonated. The grid dipper technique is differnet. You take the resonate plate load z , plate volts divided by 2 time plate current and divide by disired operating Q, 10 or so for the input capacitor, with the tank cold disconnected. use a capacity meter to set the C1 and then leave it alone, the output cap C2 is the load z ( 50) divided by q, about 2. These give the x sub c value which must be converted to capacity. Then you tap ( short coil till the analyzer shows one to one from the output jack). Hope this helps..For pi-network. check ARRL handbook for pi-l. Mike
Re: [AMRadio] PA set up using ant analyzer
The resonate plate load is the same for any class C amplifier, plate voltage divide by 2 times plate current. It is one half of the modulating inpedance. It is the same for a 6V6, 6AQ5 or a pair of 4-1000's.. Mike - Original Message - From: uvcm inc. [EMAIL PROTECTED] To: 'Mike Dorworth, K4XM' [EMAIL PROTECTED]; 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Sunday, June 04, 2006 11:12 PM Subject: RE: [AMRadio] PA set up using ant analyzer Does it matter the type of tube, 833 or 592 r Thanks Brad -
Re: [AMRadio] PA set up using ant analyzer
- Original Message - From: uvcm inc. [EMAIL PROTECTED] To: AMRadio@mailman.qth.net Sent: Sunday, June 04, 2006 8:13 PM Subject: [AMRadio] PA set up using ant analyzer Does anyone know what value resistor between the plate of and ground for a 833 and a 892r, so I can set up the tank using an antenna analyzer like a mfj 369? The resistor value is determined (exactly) from the platevoltage divided by 2 times the plate current.. About 5000 ohms or so.
Re: [AMRadio] Shorting stick
I am certainly learning here. I always thought of a shorting stick as used in 1 to 5000 watt transmitters (AM TRANSMITTERS) as a guide to put a well grounded piece of thick braid on the hv points after every thing normally done has been done to discharge any remaining stuff lurking about. The grounded braid at the end of the broomhandle, is millions of times more conductive actually BILLIONS of more time conductive the wood. The wood stored inside a power supply case is not creosoted or soaked in water. I have no qualms about holding a ground strap against a normally and supposed NO VOLTAGE point as a last defense of my life with a three foot or so piece of dry wood. Use a glass ten foot pole if you wish, I would like to be able to see how a normal wooden broom handle will not function to guide the ground point to the test points. It is better than most folks use. I have seen plastic screw driver handles depended on for this. The broom handle is a great improvement and way better than nothing. I think that if we as AM ers take away from all this that it is just cheap insurance to make sure by grounding supposed NO voltage points it will be worth while. 73 Mike - Original Message - From: John Wright [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Saturday, June 03, 2006 9:10 PM Subject: Re: [AMRadio] Shorting stick I wouldn't use wood for an insulator. Its insulation properties change drastically depending on the relative humidity. I have seen telephone poles light up quite nicely with 10K volts on them. PVC pipe (the white stuff) is a good insulator.
Re: [AMRadio] Shorting stick
Discharging is not the idea. If all is well it will NEVER discharge anything. A nail with a good hooked ground strap in a broom handle is perfect. This is to keep you from making a sudden trip to the hereafter only. If it should ever actually be called on to work you will normally holler out the name of the Christian Savior in a loud voice! This is why folks in the business call them Jesus Sticks! - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Friday, June 02, 2006 9:57 AM Subject: [AMRadio] Shorting stick I always thought you had to discharge though a high value resistance to avoid damaging arcs that would hurt the surface you were discharging through a plasma arc. I do remember using a shorting stick in a job I had 20 years ago. Alan __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] Shorting stick
On a BC-610 using a external VFO, just kill exicitation, ALL METERS fall to ZERO, the B plus will go to 4000 VOLTS and if you have bypassed the interlock and touch the link you will be GONE, Forget the meters! Trust the stick! I know! - Original Message - From: John E. Coleman (ARS WA5BXO) [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Friday, June 02, 2006 10:11 AM Subject: RE: [AMRadio] Shorting stick If you do things right, Power Down, Watch the HV meters fall down, Then - Apply the shorting stick, There won't be an arc. WA5BXO, John __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] Stock or modify? BC rig value -- Shorting Sticks
Yes. I would not want my life in the hands of an alligator, crocodile or battery clip. Since you will always use it every time it is best to make it permanent. That one time you don't could be you last time to EVER need it! - Original Message - From: Rick Brashear [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Friday, June 02, 2006 9:12 AM Subject: Re: [AMRadio] Stock or modify? BC rig value -- Shorting Sticks That ought to work. So, these shorting sticks were more or less permanently attached to the cabinet?
[AMRadio] -- Shorting Sticks
. You are not allowed any mistakes with 3kv @ almost half an amp. Half an amp? a well charged capacitor delivers way more than half an amp. A 12 guage shell goes poof compared to a full cap. being discharged with the Jesus Stick! Switch to Safety!ABC..always be careful.
Re: [AMRadio] Ferroresonant transformer revisited
How hot is the darn thing -supposed- to get? For your unit I don't know. I have used hundreds of SOLA Constant Voltage Transformers, of the 250, 500, 1000, and 3000 watt versions. They were of the CVH (harmonic neutralized..SQUARE WAVE) and the CVS (SINE wave type). The 250 watt is impossible to touch in service even with no load. They will remove skin but will work for over twenty years without fail. The 500 watters and the bigger ones being larger (having more mass) can be touched but still run warm. What these things were for was to take a voltage of 90 to 140 volts ac and maintain it at exactly 120 volts. We used them for lightning protection and they worked fine protecting what ever was plugged in; radio equipment and test equipment in the racks. They all draw current when not in use and therefor are a waste of electricity unless they are actually supplying something. Protecting a EIMAC high dollar tube filament would be a great use. We nailed them to concrete block walls vertically for convection cooling. I worked with these things 38 years and don't remember but one capacitor failing in one which was easily replaced and returned to service. Hope this non-answer helps. 73 Mike
Re: [AMRadio] shunt
I squared R is 31,250 watts. (25 amp). You are going to get the house breaker before the ammeter pegs. A nice 8 amp would handle 3200 watts and a ten is handy for 5000 watts. 73, Rick/K5IZ Rev. Don Sanders wrote: What are you planning to run on AM if you need to go from 1250 watts to 21,250 watts? Or did you just get a job with VOA.
Re: [AMRadio] shunt
If I'm not mistaken the BC-939 antenna coupler used with the BC-610 transmitter uses a 15 amp meter in the antenna output circuitry and the BC-610 is capable of only 400 watts carrier. Again it is still I squared R so at a TWO OHM load and 15 amps you would indeed have 450 watts. The way the BC-610 ran mobile is into a 15 foot whip so the resistance could be perhaps as low as 2 ohms, negelecting ground loss which is in series BUT the BC 610 is looking into a fifty ohm load into the tuner and the meter should be looking at the output. mike
Re: [AMRadio] antenna tuners transmision lines and more
- Original Message - From: Donald Chester [EMAIL PROTECTED] I recall there was a Central Electronics rig that had a no-tune broadband output network with a tube type final. They sealed the whole thing in something like epoxy, and gave no technical data on how it worked. Yes but it was a patented device and the patent number was shown. I sent for the patent disclosure and built the coil as presented. It worked perfectly and I made measurements that showed it's own impedance to be 25 ohms and it would easily match 25 to 100 ohms 2:1 SWR. Mine was for a single 813 final. As I recall the network was in some ceramic that was nearly impossible to open short of an A-Bomb and many wondered what was inside since no-tune was a mystery at that time.. Mike
Re: [AMRadio] antenna tuners transmision lines and more
Actually there are a number of commercially manufactured tube RF finals that DO indded use toroidal transformers. Dentron, for one example - they made a number of linear amps like that, and they were/are not alone. The Alpha 374 had nothing but toroids. It might be remembered as the legal limit amp that ran for months with a brick on the key.. I bet most all Alphas are the same..Had 3 each 8874's..
Re: [AMRadio] antenna tuners
I was beaten to the door on this. Actually there is a spot up about one third wavelength that is 100 ohms,for a perfectly resonate radiator. So it would be 2 to one and a dandy perfect resonate vertical with over a hundred radials is about 35 ohms so the magical 1 to 1 is nothing magical. I would beg everybody to read at least two chapters of Walt Maxwell's book Reflections. The right SWR for the wrong reason, and the Wrong SWR for the right reason. The first I would call dummy load syndrome and the second as above. This stuff is not opinion or politics it is pure science and can be tested at YOUR house.. 73 Mike - Original Message - From: Gary Schafer [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Thursday, April 20, 2006 10:12 PM Subject: RE: [AMRadio] antenna tuners This is another tidbit to keep in mind for those that still may think that an antenna has to be resonant to give 1:1 swr. A dipole antenna rarely is 50 ohms at resonance. It is very dependent on height above ground as to what impedance it presents at the feed point. It can range anywhere from below 30 ohms to above 70 ohms. So if you cut your antenna so that you have 1:1 swr at the transmitter end of the coax, the antenna is probably not tuned to resonance! You have detuned the antenna to change its impedance that the coax sees. Only rarely does a resonant antenna turn out to be 50 ohms. 73 Gary K4FMX
Re: [AMRadio] Correct tuning procedure
- Original Message - From: gwt [EMAIL PROTECTED] To: AM Radio List amradio@mailman.qth.net Sent: Thursday, April 20, 2006 6:07 PM Subject: [AMRadio] Correct tuning procedure Hi, I'm wondering if some guru out in AM land can set me straight on how to properly tune a long wire using an L network or a T network tuner configuration. I have two long wires, each 285 feet long. They feed directly into my shack, where the tuner is located. I have a tuner that I built using a BC610 external tuner roller inductor and two BC610 variable capacitors, allowing me to use either method to tune my long wires. Question #1: Which is the best method to tune with? An L network or a T network? Question #2: To reduce the losses coming from the tuner, which is best to use? The least amount of inductance you can use to get a match, or the highest inductance to get a match? Question #3: Which method will most likely give the widest bandwidth without re adjustment? Thanks, George KE4HJ http://fermi.la.asu.edu/w9cf/articles/tuner/tuner.html First go read this article. To answer the questions the L is best by a factor of 7. The L must be turned around to match either high or low but is always the most efficient. The T is just two L's back to back. This gives many chances to mistune. The correct tuning of the T is to set the capacitors at maximum capacity and use the inductance that lets the match be with maximum capacity, especially on the output side. i.e. the first dip from the minimum side of the coil. The loss is only in the coil and lots of loss will widen the match by placing resistance in parallel. In the split stator parallel coil tuner it is the opposite. Use the minimum capacity and max coil for lowest Q which will allow the match. Hope this helps. After you study the link story from QEX you will be able to do your own math and measurements and take NO One's word..There is so much misinformation around. . If you don't have Walt Maxwell's Reflections get it!.. 73 Mike
Re: [AMRadio] Re: Triode connecting 803's for a Modulator
The question was: how to do it with 803's The source listed is the Bill Orr Handbook. He calls all of the circuits Zero Bias Tetrode Modulators. Even the 807 and 813 in TRIODE connection is shown with the beam forming plates grounded. The circuit is about zero bias, and no screen supply. The 803's are shown since they were one very plentiful and cheap. My understanding of the suppressor bias is that it allows the plate voltage to swing down to it and increases both headroom ( work space) and increases efficiency. 510 watts output with clean audio is not bad for zero bias and no screen supply, The suppressor voltage is actually the voltage used on the speech amp plates which is says can be 6B4's or most any 8 watt speech amp. He does say these tube require more drive than 813's but since the then price for a new one was four dollars a tad more drive make little difference. In W6SAI's 14th edition Radio Handbook page 595, chapter 27-3. Seybold's patent no. 2,494,3176 explains the use of beam tetrodes in TRIODE connection to use no bias and no screen supply. The drive is applied to the screens and a resistor to the control grid. The 15th Edition says the grid resistors are not needed for the 803 or 813 tubes.. Hope this helps.. Mike
Re: [AMRadio] Triode connecting 803's for a Modulator
- Original Message - From: Bob Deuel [EMAIL PROTECTED] To: AMRadio@mailman.qth.net Sent: Sunday, April 09, 2006 11:52 AM Subject: [AMRadio] Triode connecting 803's for a Modulator I have a bunch of 803's. In the past, I have seen modulator articles featuring triode connected 813's. Physically, the 803 also looks like it would be a good candidate for the same application. Has anybody tried triode connecting 803's for a modulator? If so, what were the design parameters did you used? Tnx, Bob K2GLO On page 662 of the 15th Edition of RADIO HANDBOOK by Editor and Engineers. Paragraph 30-8 the use of 803 in triode connection is fully discussed. A schematic (figure 20) shows 2500 volts at 18000 ohm plate to plate being driven by a 8 watt speech amplifier through a Stancor A-4761 Class B driver transformer set for 2:1 Ratio. Eg-g =170 volts Driving power 7-8 watts Resting current = 50 mA. Power output = 510 watts Supressor volts = 280-340 volts A Chicago CMS-3 was used for the output transformer..
Re: [AMRadio] Triode connecting 803's for a Modulator
No, he had the screen and control grid strapped and fed. The supressor was biased in the center tap of the driver transformer with the voltage indicated. Mike - Original Message - From: Donald Chester [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, April 09, 2006 3:47 PM Subject: Re: [AMRadio] Triode connecting 803's for a Modulator From: Mike Dorworth, K4XM [EMAIL PROTECTED] On page 662 of the 15th Edition of RADIO HANDBOOK by Editor and Engineers. Paragraph 30-8 the use of 803 in triode connection is fully discussed. A schematic (figure 20) shows 2500 volts at 18000 ohm plate to plate being driven by a 8 watt speech amplifier through a Stancor A-4761 Class B driver transformer set for 2:1 Ratio. Eg-g =170 volts Driving power 7-8 watts Resting current = 50 mA. Power output = 510 watts Supressor volts = 280-340 volts A Chicago CMS-3 was used for the output transformer.. I assume all three grids simply strapped together. Is that correct? In some circuits with triode-connected tetrodes, particularly the 807, the screen grids are driven directly with the audio, and a resistor is placed between the screen and control grids. Don k4kyv ___ This message was typed using the DVORAK keyboard layout. Try it - you'll like it. http://www.mwbrooks.com/dvorak/ http://gigliwood.com/abcd/ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] Re: AM filter for an SB-300
- Original Message - From: Jose HF Silva [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, April 09, 2006 7:21 PM Subject: [AMRadio] Re: AM filter for an SB-300 What about DSP or SDR? The front end IF Filter establishes the overall bandwidth, the DSP would Narrow that down after the first filter.. Mike
Re: [AMRadio] 10 Meter AM Frequencies
From: Theo Bellamy I seem to remember that about 20 years ago some folks were converting 23 channel CB rigs to use on 10 meters (by legal hams, of course). I think they were just changing four of the xtals in the xtal synth circuit and ending up with 23 channels in the 10 meter band. At the time I think there was some sort of agreed upon scheme so everyone was ending up on the same 23 frequencies. Does anyone know what these are? I sure don't know, but it was written up in the QST magazine with conversion articles. Should have been in the late seventies. I might find it accidently, but have no clue where to look right now. Mike - Original Message -
Re: [AMRadio] Modulator design needed
807 in class AB1 at 400 volts 36 watts, 500 volts 46 watts, 600 volts 56 watts and 750 volts 72 watts. Usually subtract 10 to 15 percent for transformer losses etc. Almost a perfect match for the 6N2 at any voltage used.. Mike Just remember if you are going to use a tube phase inverter rather than a driver transformer the modulator tubes need to be run in AB1 and not AB2. You can't run any grid current without a driver transformer. This leaves out 807's as modulators as you can't get very much power out of them in AB1 but they are fine in AB2 as they are used in most rigs. Dx100 etc. 73 Gary K4FMX
Re: [AMRadio] Modulator design needed
6146 AB-1, 500 volts, 75 watts, 600 Volts, 95 watts, 750 Volts, 120 watts.. I thought the original question was to modulate a Johnson 6N2 which uses a 5894. Usually one uses the same Plate supply for the final as the modulator. The 6146 gives way too much power for the voltage rating the 6N2 would use, 450-600 Volts. The AB-1 807 or some of the hotter 6L6 versions such as 6L6GC seem more in the same voltage line to give the power needed. The Viking II could do the whole job with a Ceramic 4 pole, 2 position switch as shown in Bill Orr's 14 Edition Handbook (his First) It was mounted on the rear apron along with a 3 lug terminal strip. In the older 12th Edition (Editors and Engineers) there is shown a phase inverter driving 6V6's and also one driving pair 813. A 6C4 in the former and a pair of 6SJ7's in the later case. On the AM Forum Archives there is a pair of 4-400's driven in AB-1 by a pair of 2E26. Google N9FOY and click on modulator. Circuits from 6AQ5, 6V6, 807, 6146, 813, 4-400 all published and none using driver transformers shows this is an OK way to go for most any power level. Mike
Re: [AMRadio] Amplifier to use with my DX-60
Short answer. The SB200 uses a pair of 572B/T160L rated at 160 watts each. AM Linear output can not be more than one half of total dissipation. The power supplies are usually rated for continous service (AM) at 25 percent of the peak. For SB220 a 400 watt transformer is used for 2000 watts pep input. The SB200 is rated at 1200 watts pep input and would have about a 300 watt transformer. If the supply were strong enough the SB200 could run 160 watts carrier. Best to stick with one half of that..80 watts. For the SB220, L4B, TL922A best to stick with 250 watts carrier, or less. The answer below is exactly correct except for the tubes in the SB200.. The SB230 uses a conduction cooled 8873 with about 300 watts dissipation, 80 watts carrier would probably cook it in short order because of the non-cooling system heat load. 73 Mike - Original Message - From: Donald Chester [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, March 16, 2006 4:48 PM Subject: RE: [AMRadio] Amplifier to use with my DX-60 From: Alan Beck [EMAIL PROTECTED] I would like to use a cheap am with my DX-60. An SB-200-230 seems to be a Class B amp. There for it only conducts on the positive going cycle. I don't mean to sound silly, but someone told me I could run this in SSB Mode using AM input from my DX-60, I run 100 Watts carrier for 400 Watts peak, now that makes sense. What does not make sense is how do I get the other side of the wave form The Tank??? I guess the tank. The linear will work on AM as long as you don't exceed the peak power output rating. Exceeding the peak output rating will cause the signal to flat-top, distort and splatter. Another thing to watch for is the plate dissipation of the tubes. If I recall correctly, the SB-200 series uses a pair of 3-500Z tubes in the final. That means you have 1000 watts of plate dissipation available. Running AM linear @ 100% modulation will give carrier output efficiency of about 30%. So you could run maximum 1500 watts DC input to those tubes, with 500 watts carrier output, and 1000 watts dissipated by the tubes. With modulation, the tubes will actually cool down slightly, since the DC input will not vary, but the amplifier will deliver sideband power in addition to carrier power output. So some of the input power will be converted to rf in the sidebands instead of heat in the tube plates. But you also have to be careful with the power supply. AM runs at 100% duty cycle, so the power supply in the amplifier may not be rated to run 1500 watts continuous duty. After a few minutes, the power transformer may overheat. In that case you will have to run it at reduced power. But be careful that the plate efficiency does not exceed about 33%. If you run it at too high plate efficiency, it will not leave you enough headroom to accomodate the positive peaks, and flat-topping/distortion/splatter will result. Don't worry about the missing half of the rf cycle. It works with AM exactly the same way as it does with SSB. Since the amplifier is single ended and not pushpull, the missing half of the rf cycle is filled in by the flywheel effect of the rf tank circuit. In summary, with class-B linear AM operation, the final will run about 33% carrier efficiency. The peak efficiency on modulation peaks will be about double that, 67%. Two-thirds of the DC input to the final will be dissipated as heat in the plates of the tubes under carrier-only, no modulation conditions. That means the carrier output will be one half the plate dissipation of the tubes. The peak power output should be about 4 times the resting carrier output at 100% modulation, if flat-topping is to be avoided. Linear amplifier AM operation dates back to the very earliest days of radio. The earliest high power broadcast stations used it. It was used for years before anyone figured out how to run audio amplifiers in class-B. Before then, the only kind of high level plate modulation that was used employed class A audio amplifiers, usually the Heising circuit but sometimes series modulation was used. Both those systems ran at lower ovarall efficiency than linear rf amplification. Therefore, AM linears were used long before high level plate modulation for high powered AM transmitters. _ This message was typed using the DVORAK keyboard layout. Try it - you'll like it. http://www.mwbrooks.com/dvorak/ http://gigliwood.com/abcd/ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] Amplifier to use with my DX-60
YUP. The two things are the tubes and the power supply.. One half dissipation is MAX.. you are using 800 watt tubes so 400Watt carrier is max. The Thunderbolt has a real power supply, so, sure 300 watts is fine.Since SSB is 25 to 30 percent average of peaks the manufactures can squeeze in small supplies for voice or CW service. Ever make you wonder that they might allow 2500 watts input SSB but only 400 for RTTY. AM and RTTY separates the Men from the boys.. Mike - Original Message - From: Dale Smith [EMAIL PROTECTED] To: Mike Dorworth, K4XM [EMAIL PROTECTED]; Discussion of AM Radio amradio@mailman.qth.net Sent: Thursday, March 16, 2006 5:43 PM Subject: Re: [AMRadio] Amplifier to use with my DX-60 How about a Johnson thunder bolt is 300 watt carrier ok ? I hope so cause that is what I have been doing The transformer in there is twice as big as my swan mark 1. thanks ..de/dale/ka5who
Re: [AMRadio] Morrow Equipment
MY 32V3 includes the cabinet, works real good. Will let go for $4999.99 plus first class postage from Georgia.. As a bonus, the 32V2 Collins supplied manual will be included for only $74.99 extra.,with purchase. So as not to forget, order before midnite tonight.. Operators are standing by.73 Mike I would also offer a very clean 32V3 for $5000.00, but I gave the cabinet away to someone. Brett N2DTS
Re: [AMRadio] Morrow Equipment
Oh yes indeed. You will find some interesting circuitry that is all in parallel. Such as a bad capacitor for , say ten meters is killing you on forty. What a thrill it was to take the rack loose and get in there and pull the bad mica capacator out and re assemble. Thankfully I had to just do it once. You will also find interesting the double knot and figure eight loops that Collins used to hold each part in place. Must have been in case it was used in aircraft or combat tank service.A solder sucker, solder wick and couple dental picks and a good magnifing glass and some double jointed physical exercises will show you the neat way they attach each part.Lotsa LUCK.. 73 Mike - Original Message - From: DAVID O'NEILL [EMAIL PROTECTED] To: 'Mike Dorworth, K4XM' [EMAIL PROTECTED]; 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Wednesday, March 15, 2006 5:53 PM Subject: RE: [AMRadio] Morrow Equipment I HAVE A 32V3,IT ONLY WORKS ON 80 MTRS.DID YOU EVER WORK ON THE DOUBLER STAGE?ALL THE CAPS AND RESISTORS ARE UNDER THE BAND SWITCH. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mike Dorworth, K4XM Sent: Wednesday, March 15, 2006 3:28 PM To: Discussion of AM Radio Subject: Re: [AMRadio] Morrow Equipment MY 32V3 includes the cabinet, works real good. Will let go for $4999.99 plus first class postage from Georgia.. As a bonus, the 32V2 Collins supplied manual will be included for only $74.99 extra.,with purchase. So as not to forget, order before midnite tonight.. Operators are standing by.73 Mike I would also offer a very clean 32V3 for $5000.00, but I gave the cabinet away to someone. Brett N2DTS __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] FM transmitter
Yup. He is talking about rebroadcasting hambands to hambands for HIMSELF.. Permitted under aux stations in FCC rules.. Mike - Original Message - From: Warren [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Friday, March 03, 2006 5:32 PM Subject: Re: [AMRadio] FM transmitter Is it not against regulations to broadcast music etc. on the HAM Bands? Warren - Original Message - From: Rev. Don Sanders [EMAIL PROTECTED] To: [EMAIL PROTECTED]; Discussion of AM Radio amradio@mailman.qth.net Sent: Friday, March 03, 2006 10:14 AM Subject: Re: [AMRadio] FM transmitter Better yet, set a 2 meter hand held to low power and feed receiver audio into the mike jack and use another hand held to listen. I do this on simplex freq 146.55 and can go 3 to 400 feet with no problem monitoring the net freq or dxpedition freq. Healthfully yours, DON - Original Message - From: Brian Carling [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Friday, March 03, 2006 7:26 AM Subject: RE: [AMRadio] FM transmitter Yipes - for $399.00 it better be DARN good, LOL! On 2 Mar 2006 at 21:53, Bob Peters wrote: The best FM xmtr I have used is from Broadcast Vision in Ca. They are used in health clubs all over the USA. A little costly but work well. Are in Sterol and digital. The Crane does not work well. The Ramsey is very expensive.. Bob W1PE -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Miller WB5OXQ Sent: Thursday, March 02, 2006 9:28 PM To: Discussion of AM Radio Subject: Re: [AMRadio] FM transmitter Get some wireless speakers. They come with a small 900mhz transmitter and usually work up to 150' though they claim 300. Around $60 a pair at radio shack - Original Message - From: Donald Chester [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, March 02, 2006 4:40 PM Subject: [AMRadio] FM transmitter Hope they don't measure the FM broadcast transmitter I have, so I can listen while doing stuff around the house and yard with a walkman, its over a watt I think... What kind of FM transmitter do you use? I have been looking for something so I can use to feed streaming audio from my desktop computer to all the FM radios on my property, so I don't have to sit in front of the computer to listen. I ordered one of the little FM stereo xmtrs from C Crane. It had good synthesised frequency stability, but the audio was distorted and it had a range of about 35 feet. I need good solid coverage within a radius of at least 100 feet. I had intended to experiment with an external antenna with the thing, but it crapped out before I could do that. They refunded my money. I think Ramsey sells kits, but I have heard they are pieces of crap. Don k4kyv ___ This message was typed using the DVORAK keyboard layout. Try it - you'll like it. http://www.mwbrooks.com/dvorak/ http://gigliwood.com/abcd/ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] 6BG6 ad
Maximum voltage for the 6L6 is 360 volts. Fot the 1614, it is 500 volts. That is why the ranger, which uses 500 volts or a bit more uses the 1614 instead of the cheaper 6L6. The 1614 is RF rated as a transmitting tube while the 1614 is not. A 6L6GC is a pretty close relative.. My $0.02..Mike - Original Message - From: W5OMR/Geoff [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, March 01, 2006 8:04 AM Subject: Re: [AMRadio] 6BG6 ad Jim candela wrote: Hmmm, Well it seems like the ads claim is true, verified by Mahlon, K4OQ. In that case I reiterate, this is one heck of a deal. Try pricing the 6L6GC from any source NOS or new, and compare. How many AM rigs use the 6L6 as modulators? Johnson Ranger (is this correct?) 1614 7027 How many others? Yogie/KC5MIP had a Temco that used (4) 6L6's in the Modulator stage. I want to say it had a pair of 807's in the final, but I don't remember, exactly. Ronnie/K5WLT built a modulator for his Knight Kit T-50, just after he graduated up from being a Johnny Novice, to General. That's an interesting modulator, in that it uses a pair of 6L6's and was built from a Popular Elextronics magazine article, from back in the mid-to-late 50's. One of those 6L6's is apparently slightly microphonic. He can take the plastic handle of a screwdriver, hit the metal 6L6 and the tube 'rings' like a bell. Ronnie has had so much fun with that rig, running a single 807, modulated by a pair of 6L6's... and has worked all over the country with it. I, myself, have plugged in 6L6's into the Ranger, and Rager II I had, back before I got the titanic. I've got an old audio amp here, that I got from John/W5MEU that runs either a pair, or 4, in p-p paralell. 6L6's are populare everywhere. And, while the engineers mght have decided to use either 1614's in the Rangers, or 7027's in the Ranger II's, I couldn't tell a nickles worth of difference in the rigs that I had, between those tubes, and the 6L6. Just my .02c. Do I get change? ;-) -- 73 = Best Regards, -Geoff/W5OMR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] 1930's Old Buzzard Open Rack TransmitterFinallySeestheAirwaves! (Long)
811/812 CCS phone dis is 27 watts with 82 watts output. 811/812 ICAS phone dis is 40 watts, with 120 watts output 811A/812A CCS Phone dis is 30 watts, with 85 watts output 811A/812A ICAS Phone dis is 45 watts, with 130 watts output. Per RCA Transmitting tube manuals..Sadly, page 21 is missing from my Taylor Catalog. Taylor did not use ICAS Ratings to my knowledge. RCA introduced those with the 1941 Tube Guides.. The 1939 ARRL handbook, page 80 shows the phone ratings for the T-55 as 1500 volts and 150 plate mills.Peak power output of 652 watts and a carrier power of 168 watts..With the input of 225 watts and a output of 168 watts, then the CCS Phone dissapation would have been 57 watts. Mike From: Brett gazdzinski [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Tuesday, February 21, 2006 10:44 PM Subject: RE: [AMRadio] 1930's Old Buzzard Open Rack TransmitterFinallySeestheAirwaves! (Long) The T55 has 55 watts of plate dis, and gives 170 watts out? The 812A has 65 watts of plate dis and gives 130 to 150 watts out?
Re: [AMRadio] 1930's Old Buzzard Open Rack TransmitterFinallySeestheAirwaves! (Long)
811/812 CCS phone dis is 27 watts with 82 watts output. 811/812 ICAS phone dis is 40 watts, with 120 watts output 811A/812A CCS Phone dis is 30 watts, with 85 watts output 811A/812A ICAS Phone dis is 45 watts, with 130 watts output. Per RCA Transmitting tube manuals..Sadly, page 21 is missing from my Taylor Catalog. Taylor did not use ICAS Ratings to my knowledge. RCA introduced those with the 1941 Tube Guides.. The 1939 ARRL handbook, page 80 shows the phone ratings for the T-55 as 1500 volts and 150 plate mills.Peak power output of 652 watts and a carrier power of 168 watts..With the input of 225 watts and a output of 168 watts, then the CCS Phone dissapation would have been 57 watts. Mike From: Brett gazdzinski [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Tuesday, February 21, 2006 10:44 PM Subject: RE: [AMRadio] 1930's Old Buzzard Open Rack TransmitterFinallySeestheAirwaves! (Long) The T55 has 55 watts of plate dis, and gives 170 watts out? The 812A has 65 watts of plate dis and gives 130 to 150 watts out?
Re: [AMRadio] 1930's Old Buzzard Open Rack Transmitter Finally SeestheAirwaves! (Long)
811/812 are 6.3 volt filament, the T-55 is 7.5 volts..otherwise similar to the 811 NOT A.. Mike - Original Message - From: Brett gazdzinski [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Tuesday, February 21, 2006 4:08 PM Subject: RE: [AMRadio] 1930's Old Buzzard Open Rack Transmitter Finally SeestheAirwaves! (Long) What is the difference between a T55 and an 812/812A? I know a V70D is good for more power, but has different filament voltages... I think I have some T55 tubes, never knew they would do as 812 substitutes. I thought they looked lower power (smaller plates). The amount of turns on the link coil impacts what you can load up to a LOT. I made my own link for the 812a rig, and had to try various link turns before it loaded up right. I have the series cap also, and that does change how the rig loads up, but does not seem to change the efficiency or anything else. At 1500 or more volts, I run the 811a's at zero bias, the 812A's run 340ma cathode current, 70 ma grid drive, 275 watts out with no color on the plates. The 812A's get fixed and LOADS of grid leak bias... I have tried 811A's in the RF deck, they seemed to work just the same as the 812A,s. Good deal on getting the old rig running! Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ne1s Sent: Tuesday, February 21, 2006 3:27 PM To: AM Radio Reflector; [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: [AMRadio] 1930's Old Buzzard Open Rack Transmitter Finally Sees theAirwaves! (Long) Hello, Some of you may remember that a few weeks ago I posted a question regarding optimizing the layout for a push-pull triode HF final deck, given that the deck in question was already partially built (by someone else). This was a component of a larger project involving completion/restoration of a 1930's vintage homebrew open-relay rack AM transmitter I had initially acquired some 15-20 years ago, and has been sitting patiently in my cellar shack since this time waiting for me to ge a round tuit. Well, the elusive and highly-coveted tuit finally arrived about a year ago, when I started drilling and blasting for the modulator deck. I had to take a rather long break from itarting last July, when I started a major effort to bring a majorly-hacked Johnson Valiant back from the dead for a friend which led to the birth of FrankenValiant. But that's another story for another time. With FrankenValiant finally completed, I finally got back to the project at hand a month ago, and to make a much longer story less so, the transmitter made its maiden voyage on the airwaves last Sunday evening, when I used it during the final 2 hours of the AWA AM QSO party, on 75M. The final presently uses a pair of 812s, which are modulated by a pair of 805s. When the debug/shakedown stage is over I'll switch over to T-55s in the final (harder to find, and more expensive, than 812s). There are still a few problems, which I hope to rectify next weekend: (1) My bias supply for the modulators and finals, built onto the modulator deck, failed. I had used a period resistor from the junkbox - it was working, now it's opened up. Replacing it will involve removing the modulation transformer from the deck (to make the weight more manageable, removing the deck from the rack, replacing the resistor, and assembly in reverse order of disassembly. So my on-th-air use was with grid-leak bias only on the finals, and zero-bias on the modulators (the 805s were still operating within their ratings, though). (2) The speech amp has an intermittent noise which modulates the finals quite nicely when it is present. No surprise: all the caps in the deck are original wax-paper. I did check the DC blocking caps for leakage beforehand (by measuring the DC grid voltages), but guess I shouldn't have trusted them. A little benchwork with the 'scope should trace down the faulty component. It's in the first stage, 'cuz its intensity varies with the mic. gain control. I actually saw it on the scope when I was checking out the speech amp initially, and made a conscious decision to deal with it later. (3) The link output is directly feeding coax which directly feeds the antenna tuner, and I can only load the finals up to ~150 mA for about 160W output. Should be able to load them to nearly twice that. I need to install a series breadslicer to resonate the link. (4) I need to improve the grid drive on 10M. (5) I want to use a spare set of relay contacts to disable the speech amp (by removing the B+) on standby (receive). And, finally (pun intended), I would like to thank all those that answered my question concerning the layout of the final PA deck. If you'll recall, What I had to work with was the two tube sockets
Re: [AMRadio] word for word
Never ever once has it 1000 watts carrier power level PERIOD. So how could it be reduced? It was 1000 watts or 900 watts INPUT regardless of effeciency, Class C being the best.. About 700 watts. Without meters to measure accuractly it was 900 watts INPUT. With a Linear the 1000 watts in would get you a coupla hundred watts at best. The PEP OUTPUT was deemed easy to measure with standard PEP meters. Sure we lost aboout 50 percent at full modulation but could use grid modulated, linears, or poor quality tank circuits and only had to measure the power OUTPUT. Life ain't always fair.. I was here for 52 years watching. They stole the 11 meter band from us also in 1958. Want it back? Mike Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, February 02, 2006 4:33 PM Subject: [AMRadio] word for word 1. Thank you Paul/VJB for the courtesy and seeing my 'faux paux' in the wording...good example of Ham espirit in practice, right there from that gent. 2. I had to leave Ham radio back in 1965...as per political orders from Washington to destroy Asian countries and kill people there...got my license back 3 years ago..along with my original call...so... why did FCC reduce the 1000 watt carrier power level? __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] Pro AM heat on FCC?
Hold on there! It was 1000 watts DC input on the meters. With no meters it was 900 watts maximum INPUT! With class C, High level that could be 70 percent, i.e. 700 watts carrier, with a grid modulated (can you say Linear?) then it was about 330 watts carrier or maybe even 250 watts.. Eggs are eggs and oranges are well, you know. You want only High Level 1 KW input with multiple efficiency or a standard output read on standard meters? Back to just reading and not talking. 73 Mike - Original Message - From: Ben Dover [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, February 02, 2006 2:56 PM Subject: [AMRadio] Pro AM heat on FCC? Hello Steve Snip! Nevertheless, I wanted to put some heat and noise from a Pro-AM direction to let the FCC folks know there are some opinionated AM'ers working the bands who do not want any future restrictionsthey were talking about it this go around. And...while I was at it...thought I'd ask for more respect...namely AM-use only segments so as to diminsh the AM/SSB elbowing...and add some of that Pro-AM heat. Snip! It may be beating a dead horse, but I'd like to see an attempt to restore the OLD AM power level of 1000 watts of carrier! Even if the effort fails, if we make enough noise about it the attempt might might well give a LOT of folks out there pause for though before assaulting us again! Mr. T., W9LBB __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
Re: [AMRadio] UG 634U
I have a Millen ad in a 1963 CQ Magazine that says the Red and Black Millen connectors are for HV and the Brown (yellow) is a special filled bakelite for RF use ONLY! My friend says the Reds are the best since the Black are pigmented with carbon to give the black color. Sounds right. Mounted on a plastic disk they do count as pretty good. Metal screws are asking for trouble. Nylon handy for this. 73 Mike. - Original Message - From: Mike Sawyer [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Sunday, January 29, 2006 6:11 PM Subject: Re: [AMRadio] UG 634U Unfortunately Ed these are the 'Millen' connectors are only good to about 2KV. I know the spec say more but this was discussed at length on the AMPS reflector. I have a bunch of the brown ones where the flanges apparently broke down under HV stress. I couldn't prove it but the insides of the material looked to have been molten. Mod-U-Lator, Mike(y) W3SLK - Original Message - From: Edward B Richards [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, January 29, 2006 5:47 PM Subject: Re: [AMRadio] UG 634U I got my high voltage connectors from RF PARTS[EMAIL PROTECTED] part # 37001 (A,B,C,D) rated for 7000 VDC @ 2 amps. Chassis mount flang $6.90, cable mount shell $5.90. Good luck. 73, Ed Richards K6UUZ
Re: [AMRadio] Good solid state/hybrid rigs for AM use
Keep in mind, when you run the 32V2, you should get 80/90 watts out in the high voltage position (and should have solid state rectifiers), but running an ft101, and others of its ilk, you get about 20 watts out. My 32V3 gets 107 (exactly) watts out in HV position with 121 volts AC input and using the original tube rectifiers. I would be afraid to use solid state rectifiers even though I have them on hand. Maybe some day when the tubes go bad and I use LOW voltage I will try them.With 2 used, 1 new 4D32 tube I get the the same results.. 40 meters as reference. I get good reports on a TS-570D with a 444D mike using a 3 tube 811A amp. It all works if not overdriven.. 73 Mike
Re: [AMRadio] WTB/WTS and a question
The tubes all have 2V filaments. The radio has two inputs for a filament supply, 2V or 2.5V (the 2.5V input merely inserts a series resistor). My question iswhy did anyone manufacture 2V filament tubes and Two volt tube were used in the 19 twenties and thirties for FARM radios. They used a 2 volt wet cell. One third of a car battery for those tubes. Also The audio always push pull class B triodes for maximum B battery utilization. Folks carried the cell to the service station or perhaps had a windmill generator from a T model Ford connected for recharging. REA did not start until about 1933 or so and almost no Farmer in America had Electric power. The dry B batteries were 135 volt and lasted a long time but many units had a vibrator pack that ran off a 6 volt wet cell battery from a car or the Edison Electric Company. By the mid 1930's the 230's etc were amost obsolete. Hope this helps HNY, 73 Mike
Re: [AMRadio] Want Ranger pwr xfmr
Hello John. The filament windings should be on the outside and should be fairly easy to remove and or replace. I have done it many times. You have nothing to lose. Drive out a coupla laminations and pull the e and i out. Then peel it like a onion and fix it.Use Scotch plastic tape and put er together again. It will work as new. 73 Mike k4XM - Original Message - From: John Lawson [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: amradio@mailman.qth.net Sent: Friday, November 25, 2005 12:36 PM Subject: [AMRadio] Want Ranger pwr xfmr Anyone happen to have a NOS or Good-Used Ranger power transformer for sale? I need one - or a Good-Used Ranger - or, a new hobby... ;} After several hours on the bench last night - it is apparent why this old girl was shelved - it came to me with a 5R4 in the HV socket, but the fils didn't light, tho the tube was good. So sure enough - someone had tied the 5V fil lines back, and there was a 10-ohm 10W resistor in series with the B+ lead. I made a plug-in SS rectifier, installed it, switched the rig on - and blew both diodes and both line fuses to little bits. Ok. So I restored the original circuit - there is a definite 'under-load' short from the HV rect fils to the HV winding. Ok.. Disconnected all that - the LV side works fine, Osc runs, buffer runs - can 'zero-beat' to a receiver, frequency of VFO seems accurate. Ok... Tansformer voltage and resistance checks are within 10% of spec. Ok Put new diodes in put a Variac and ac ammeter in the mains line, turned it up slowly - POW. Actually, with the diodes in cicuit, it appears to the Variac / AC Ammeter that the power transformer has a dead short. Having replaced the filter caps, and checked the plate choke - it ain't them. The B+ line resistance is slightly over 20K. Ok...! In this process the power transformer has begun to get slighly warm, so I went back to checking the LV side - as I was testing, the transformer started to arc internally - and resistance measurements now show the fil-to-HV short. So: It's toast.
Re: [AMRadio] Tansmitter power reduction (Ranger)
The way the secondary is wound all the final and lv passes through the winding so you would have TWICE as much current if you use just the low voltage taps. BTW the Ranger modulation transformer is (by my measurement) 7083.8 ohms plate to plate primary, 3568 ohms centertaped (892 ohms each side) secondary. or 1.9837 z stepdown, 1.4085 step down turns ratio. Nominal 7000 to 3500 ohms. About 15 watts Audio level, used at 32.5 watts ICAS voice. Hope this is helpfull. 73, Mike - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, November 16, 2005 10:11 PM Subject: [AMRadio] Tansmitter power reduction (Ranger) On Wed, 16 Nov 2005, John Coleman ARS WA5BXO wrote: I don't know if the power supply come from the same XFMR or not but what does 10 on the knob mean? In the Ranger, the LV feed to it's rectifier is from two equidistant taps between CT and the 'ends' of the HV secondary, the which ends feed the HV rectifier. I'm a bit worried that if I run the whole radio on the LV winding, it will stress it. If anyone has any concrete real-world actual experience with doing this, I'd love to hear how it worked out. Guitar (and other musical) amplifiers traditionally have their volume knobs marked 0 - 10, thus '10' is 'loudest'. From whence derives the joke in Spinal Tap - This amp was custom made for me - see? the knobs all go to *11*!!! Cheers John KB6SCO __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Re: [Johnson] Amp advice
Normal wake up time is one tenth of a second to allow heating of the filament and charging of the capacitor. To be really certain, let it warm up a full minute before honking down on it real hard...MIKE - Original Message - From: John Lawson [EMAIL PROTECTED] To: Ed Tanton [EMAIL PROTECTED] Cc: amradio@mailman.qth.net; [EMAIL PROTECTED] Sent: Saturday, October 29, 2005 7:41 PM Subject: [AMRadio] Re: [Johnson] Amp advice On Sat, 29 Oct 2005, Ed Tanton wrote: Well... just my 2 cents, mind you... but it's bad enough using a linear for AM, considering the efficiency yielding only a little more signal than talking louder would accomplish... but a **SINGLE** 3-500Z combined with all that INefficiency? Complete waste of time and 3-500Z after (what will be) short-lived 3-500Z. Thanx Ed! Well: Nummer One - It's only a Hobby. As in: to have fun with. Nummer Two - I got the AL-80 and Tuner pretty cheap. (SK estate) Nummer Three - I have a Ranger and a Valiant. The Ranger needs a couple of minor 'tweaks'; the Valiant has a few things that need fixin', and that equals time and money, thus I'll go with what I have, and work on Improvements later.. Nummer Four - I'm actively looking for a Thunderbolt - none on the hook right now. Nummer Five - No one's actually *answered* the questions I have about 'waking up' the amp. (Yet, at any rate.) There has been some very pertinent and helpful advice, however - much appreciated. Nummer Six - see Nummer One. Don't curse the QRP - light a Filament! Cheers John KB6SCO __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Charcoal Briquettes and High Voltage Power Supplies
Sure don't want to fight on Sunday..but..most circuits avoid dropping more that 500 volts across any one resistor, An example is metering circuits where 1 meg resistors are series to make the total so that no single resistor drops too much. There can be 5000 volts on the string, just limit each one to about 600 volts. Mike - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED]; amradio@mailman.qth.net Sent: Sunday, October 30, 2005 1:52 PM Subject: [AMRadio] Charcoal Briquettes and High Voltage Power Supplies In defense of the common carbon composition resistor... On 30 Oct 2005 at 9:35, [EMAIL PROTECTED] wrote: Carbon comps aren't the most stable resistors in the world, and if they age unevenly you've got a problem. Worse, they usually have a max voltage rating of only a few hundred volts, so in many designs they're being overstressed. Er, not so - they are regularly used in commercial power supplies in the 1000V to 2000V DC range. Most amateur radio tube rigs used final HT of around 600 to 900V DC and they used carbon resistors too, so I'm not sure where you got that idea from, but it is erroneous. Many audio amplifiers and modulators use 400 to 800V or more. Often a lot more. As far as I know they all used carbon resistors. If it still works after 10 years then I don't think it is fair to call this results of such a design overstressed. (Runs and ducks for cover...) __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Re: [Johnson] Amp advice
75 percent is heat, 25 % in feed through power. 24 two watters going to get nice a warm. (48 watts) best use a FAN! - Original Message - From: John Lawson [EMAIL PROTECTED] To: Jim Brannigan [EMAIL PROTECTED] Cc: amradio@mailman.qth.net; [EMAIL PROTECTED] Sent: Sunday, October 30, 2005 1:57 PM Subject: [AMRadio] Re: [Johnson] Amp advice On Sun, 30 Oct 2005, Jim Brannigan wrote: If you look in the BAMA archives under Johnson Thunderbolt, there is a schematic and parts for a 6db power attenuator. The parts are available from Allied. Snagged it - Thanks! 24 2W non-inductive resitors - I gotta get a new tip for my soldering iron... ;} Cheers John KB6SCO __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Amp advice
It seems we're back to where we were. In theory the maximum carrier is limited to half the tube dissipation. i.e 250 watts. The power supply is good for about half that amount. This means the Ranger can put out at MAX around 12 to13 watts. The carrier about 125 watts, the pep output about 500 watts. Your ability to buy power transformers and tubes may vary.. Hope this helps.. Mike - Original Message - From: John Lawson [EMAIL PROTECTED] To: amradio@mailman.qth.net Cc: [EMAIL PROTECTED] Sent: Saturday, October 29, 2005 4:25 PM Subject: [AMRadio] Amp advice I have recently acquired (from the estate of a Silent Key) an Ameritron AL-80 (not A, B, or C) and the Ameritorn ATR-15 tuner. These were used together for years, then sat for an unknown length of time before being disconnected and moved. I am the second owner. The tuner exhibits constructional saliency with masonry defecatoria, and appears to be in nearly factory-new shape internally - the case is dusty a bit, but also very nice. The amp, [while modified slightly with some extra ventilation holes and a large power-transistor type heatsink bolted to the case adjacent to where the 3-500Z lives], seems to be visually in good shape - it seems to have had one of it's power-equalizing resistors (on the rectifier/filter board) replaced. It's wired for a 220 mains supply, which I will also operate it on. Initially I'll be driving the AL-80 with a Ranger, thence into the ATR-15, 450-ohm ladderline to the 450' fence-top loop guarding my back yard. I've completed the re-route of that ladder-line following previous suggestions and admonishments, BTW - and thanks to y'all for that!! I've not owned a higher-power amp before, so aside from the usual caveats concerning powering up 'older' gear for the first time - I was wondering if there are any Ameritron-specific gotchas to be aware of - and certainly if there is any wisdom, anecdotes, or cautions concerning this amp - especially as I'm going to use it on AM fone - I'd be appreciative of the experiences you've (collectively) had. Cheers John KB6SCO __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Amp advice
Good point. The Ranger modulation transformer is 7500 to 3500 ohms and rated for about 15 watts audio level. It was used at 32.5 watts for voice service which is A-OK. As example the famous ART-13 transformer is rated at 50 watts and we all know that they will do plenty more for VOICE service. The mod transformer that has to pass the magnetizing final current requires very careful spacing of the core gap. Broadcast service gets by this at the higher powers by using a choke and capacitor to shunt feed the final. This allows more BASS. They have to do 50 cycles ( Hertz for new guys). . Remember, the less load drawn through the secondary of the stock Ranger modulation transformer, the better the audio is going to sound, stock out of the Ranger. The reason being, there's less plate current being drawn through the secondary of the modulation transformer, and therefore less chance of core-saturation, cause the hysteresis curve of the transformer not to be as linear as possible. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] Re: need help
That would do the bias supply but he is talking about the peak RF voltage to make the tube work. Peak RF voltage is a hair less that the 130 volts for grid current less AB-1 operation. - Original Message - From: [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Saturday, October 22, 2005 12:20 PM Subject: RE: [AMRadio] Re: need help What about using a 130 volt 5 Watt zener diode in the cathode? On 21 Oct 2005 at 21:48, Gary Schafer wrote: I just looked up the 4-400 and I see it requires more bias than I had remembered for AB1 operation. It requires -130 volts with 2500 on the plate and 750 on the screen. So a 50 ohm resistor with 100 watts would only provide around 100 volts peak drive voltage. Not quit enough. A 100 ohm resistor should provide around 140 volts peak with 100 watts. That should work with little drive to spare. Probably the easiest would be a 200 ohm resistor (close to the 170 ohm resistor). A 4:1 balun should match it close to 50 ohms. A 200 ohm resistor and 100 watts should provide close to 200 volts peak drive voltage. I did this setup (balun and resistor) with a pair of grid driven 1625,s driven by my 20A. It worked well. Voltages were less of course! Stray capacitance will change things a bit. 73 Gary K4FMX -Original Message- From: [EMAIL PROTECTED] [mailto:amradio- [EMAIL PROTECTED] On Behalf Of ne1s Sent: Thursday, October 20, 2005 12:30 PM To: Discussion of AM Radio Subject: [AMRadio] Re: need help With a 50 ohm grid load on 4-400s, I think you'll find you'll get very little amplification from the stage - the 40400 grid(s) want(s) to see more voltage. I went throught this exercise one (on paper), so went with a 1:16 balun into a 800 ohm non-inductive resistor network in the actual design. Problem was, I couldn't make it broadband enough to cover more than 3 consecutive bands at a time, and finally resorted to a T network on the input, loaded with about 2000 ohms worth of resistors. -Larry/NE1S Gary Schafer writes: The input impedance should be very near what the value of the resistor is. In this case 170 ohms. The 4-400's will most likely be run in AB1 so no grid current. I would put in a 50 ohm resistor instead. You should get enough drive with it. Figure what the bias voltage will be on the tubes. Then figure what the peak voltage will be from the exciter at 50 ohms. If the peak voltage will be greater than the bias voltage on the tubes then you have enough drive. 73 Gary K4FMX -Original Message- From: [EMAIL PROTECTED] [mailto:amradio- [EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Wednesday, October 19, 2005 10:46 AM To: amradio@mailman.qth.net Subject: RE: [AMRadio] need help I'd have used an MFJ 259B to actually measure the input Z. Alternatively, you can always use a small tuner to tune the input. I do that anyway with my Drake L4B, (use a small MFJ mobile tuner with meter). 4-400's, eh? Nice amp! If your plate voltage is high enough, you ought to get serious power out of that baby! 73, Ed, VA3ES From: Edward B Richards [EMAIL PROTECTED]: I want to drive a linear amplifier with a rice box that requires a 50 ohm load. The linear amp uses an input to a 170 ohm, 80 watt swamping resistor to ground, then through a .001 mfd capacitor, then through a VHF parasitic suppressor consisting of 4 turns of wire around a 47 ohm resistor, to the grids of a pair of parallel connected 4-400A tubes. What I need to know is the impedance of the input. Is it close to 50 ohms or do I need to use a matching network between the rice box and the linear amplifier. __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami __ AMRadio mailing list Home:
Re: [AMRadio] Minature Mobile Transmitter
OK, from the top. There are several dozen examples of mobile rigs in QST, CQ magazine and both the ARRL Mobile Book and both CQ Mobile Handbooks all of which use a 12AX in class B, zero bias. So they must work OK. I have run mobile AM with the 12AX7 modulating a 5763 so there can be no doubt it works. In the 14 th Edition of the Radio Handbook edited by Bill Orr on page 452 is a Modulator using a 12AX7 that modulates a 2E26 at 12 watts input. Using a plate to plate load of 18000 Ohms and 300 volts the 12AX7 delivered almost 7 watts of SINE WAVE audio. As stated earlier, the inexpensive power supplies of those days furnished 300 volts at 100 ma. A Class B audio system could produce 6 to 8 watts of audio to run a 12- 15 watt input mobile rig. There was then, and it remains true today, that no known tube other than the 12AX7 had such a a low resting current of 6 - 10 ma. With a peak of 40 ma the modulator will use about 50 ma total to run mudulator including the pre-amp, usually a 12AU7, this leaves 50 ma at the 300 volts to run a oscillator, buffer if needed and drive a final and furnish it's screen grid. This is another 50 ma. So then the 100 ma is used up. The ARRL Handbook for 1960 clearly shows this to be the correct tube for the job. Without looking it up, I seem to remember about 70 ma idle for a pair of 6AQ5s which pump out FIVE watts? This all started with a question if the ARRL Handbook was misprinted. Several dozen successful rigs printed in standard Mobile Manuals , QST, CQ etc makes it a correct choice under the required circumstances.. As a extra bit of information, all of the old farm radios for the AM band of the 20s, 30s and 40s all used TRIODES in Class B to conserve battery power in the audio driver and output circuits. Ditto all of the original transistor radios of the 50 and 60,s used class B audio to keep down the current drain. - Original Message - From: [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Tuesday, October 04, 2005 5:21 AM Subject: Re: [AMRadio] Minature Mobile Transmitter On 3 Oct 2005 at 0:39, Bob Bruhns wrote: That's amazing. Can't argue with success. And the 7.5W-300V-16K p-p adds up. The published 12AX7 plate dissipation spec must be overly conservative, and the cathode must be pretty efficient. I always thought of the12AX7 as an audio preamp tube. It is... There HAS to be a good reason why manufacturers used things like 6AQ5 and 6BM8 for 4 watt audio output stages instead of a 6C4 or 12AX7 !! __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Minature Mobile Transmitter
For class A audio,with a pentode, you do not need a step down transformer of 2.66 or 5 to 1 to each half of the secondary. You don't need push- pull, and it is OK to use cathode bias which can never be used for class B. Zero Bias Class B triode operation is to save current while idle and take a big peak for a little while. Class A is a power waster, that is why the majority of later car radios used a single Class A Transistor. The cars had bigger batteries and alternators. Ditto the 6V6, 6AQ5, 6K6 output stages. Notice that all the old communications receiver that used the single ended Class A stage called for 10 percent distortion, Ugh! - Original Message - From: [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Tuesday, October 04, 2005 5:21 AM Subject: Re: [AMRadio] Minature Mobile Transmitter On 3 Oct 2005 at 0:39, Bob Bruhns wrote: That's amazing. Can't argue with success. And the 7.5W-300V-16K p-p adds up. The published 12AX7 plate dissipation spec must be overly conservative, and the cathode must be pretty efficient. I always thought of the12AX7 as an audio preamp tube. It is... There HAS to be a good reason why manufacturers used things like 6AQ5 and 6BM8 for 4 watt audio output stages instead of a 6C4 or 12AX7 !! __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Re: Minature Mobile Transmitter
The resting current is total for both sections. 10 ma would be 1.5 watts per section at 300 volts. Peak current is 35 ma total for the two sections. Works very well. Tube life not a problem. These were used for years in mobile requiring a total of 100 ma for final, osc and modulator. The last ten ma were taken from a large output capacitor when total current was about 110 ma on a 100 ma system.A single 12AU7 was used for mic preamp and driver, consumed about 4 ma. Current was measured in mills by each ma Not a single one was wasted. 6 volt cars were lucky to have a 15 to 30 amp Generator. Even as late as the mid fifties on 12 volt cars a 35 amp alternator was special factory order. No one wasted MA in mobile. Hence the zero bias tubes, 1635 and 12AX7. A 1635 will modulate 100 percent a 50 watt rig and automatically hi level clip and increase talk power without splatter.The Johnson Mobile used bias for the modulator, look up the circuit on BAMA! - Original Message - From: Patrick Jankowiak [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, October 03, 2005 7:06 PM Subject: [AMRadio] Re: Minature Mobile Transmitter What I don't get is the tube current ratings, and, was tube life a concern? 300V zero bias gets you 8mA per section, and is also 2.4 watts dissipation! I suppose these are the ICAS ratings :-P -and that's zero signal. The curve is very linear from 2mA to 8mA and even pretty good down to 1mA idling current. -but those would take bias. PJ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
[AMRadio] 12AX7 Modulators
From Radio Amateurs Mobile Handbook, 1st edition edited by Bill Orr, W6SAI. Page 85. The 12AX7 makes an excelent class B modulator for low powered mobile transmitters. Operting at 300 volts it requires no bias with a resting plate current of 10 ma. This is lower than ANY tube capable of producing the same audio power. 6N7, 35 ma, 1635, 11 ma, push pull 6AQ5 draws minimum of 70 ma when the stage is OVER biased. The 12AX7 will deliver 7 watts of VOICE audio with negligible distortion at 300 volts . The plate current will rise from 10 ma resting to about 35 ma on voice peaks. Two 12AX7 tubes may be used in push-pull parallel to obtain 15 watts of audio power. The CORRECT load impedance for a single 12AX7 is in the vicinity of 14000 ohms. Two tubes in push-pull parallel require a load impedance of 7000 ohms. On page 92 of the same manual is a 12 watt mobile, 3 band transmitter running 12 watts input which delivers 8 watts of FULLY modulated carrier which was modulated by a single 12AX7 at 300 volts.
[AMRadio] Minature Mobile Transmitter
From QST, September, 1952 Class B modulator. The 12AX7 modulator tube delivers approximately 6 watts output. From QST, November, 1951 A Deluxe Mobile Transmitter for 14 and 28 Mc. Two 12AX7s- each tube having similar elements in parallel- operate at zero-bias in Class B modulator circuit which delivers approximately 15 watts output. (300 volts) ARRL Mobile Manual 1st edition, page 178, The modulator employs a type 12AX7 tube and delivers approximately 7 watts output. 280 volts resting 10 ma, peak 30 ma. QST, December 1956 . 10-12 watts input 50 mc mobile transmitter designed to operate on the most INEXPENSIVE power supply readily available (for mobile) . The modulator tube is a type 12AX7.the modulator plate current should jump 20 to 25 ma above the no-signal value of 6 ma. From ARRL Handbook, 1960, 37th edition, page V17, 12AX7, 300 volts, 0 volts grid bias load resistance 16 k ohms output power 7.5 watts.
Re: [AMRadio] GG 813 Linear in GE Ham News -12AT7 12AX7
well. there are several dozen examples of this in the mobile handbooksCQ magazine and QST,both of the CQ books and all five of the ARRL's. It was done to get lots of audio, very low resting current, ditto 1635, a special 6N7 with zero resting current gives 14 watts sine wave RMS, can be made to modulate 50 watts with reasonable tube life. Remember, speech is 20-25 percent of peak when viewed as average. That is why 3 kw Alphas only have 1kw CCS supplies!.On the 12AX7, my mobile used this for years and no tube ever failed. Lotsa good audio!.. Mike - Original Message - From: Patrick Jankowiak [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Saturday, October 01, 2005 10:15 AM Subject: Re: [AMRadio] GG 813 Linear in GE Ham News -12AT7 12AX7 don't laugh too hard, In the ARRL handbook it claims 8 watts audio from an 12AX7 in zero bias class B push pull into 8000 ohms. I have never understood that one, if you look at the currents stated in the book, they seem pretty high for the tube. PJ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] 813 GG Amp
Not sure. Radio Handbook, 17th edition page 682, Utility 2 KW Linear pair 813's GG, also Radio Handbook 23rd edition page 17-6 An 813 Economy Amplifier for 160 or 80 meters pair 813 GG. Most of the other handbooks show the tetrode connection that would be applicable to any tetrodes including 813 which would be grid driven. Hope this helps. Mike - Original Message - From: Bob Maser [EMAIL PROTECTED] To: AMRadio amradio@mailman.qth.net Sent: Friday, September 30, 2005 1:28 PM Subject: [AMRadio] 813 GG Amp Why is it that my 21st edition Bill Orr Radio Handbook does not show the 813 amp? Even the page numbers are arranged differently. Bob __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] GG 813 Linear
1. William I. Orr, W6SAI, Radio Handbook16th Edition, section 29-8 An 813 Grounded Grid Linear Amplifier 2. William I. Orr, W6SAI, Radio Handbook, 21st edition, chapter 22 3. Bill, Orr. W6SAI (SK) Ham Radio, May 1980 Pages 47, 48, 49,50, 51. ( Ham Radio Techniques) The last is the best, uses zener (adjustable) for proper bias, Transceive relay and includes input circuit, so necessary for today's modern rigs. Also has operating conditions for a CLEAN signal, 2500 volts , 60 ma idle, peak plate current 450 ma, 50 ma grid (total) , 3000 ohm plate load Z, drive impedance 135 ohms, 1120 watts input, 680 watts out, 28 watts drivepower. This HR article has a good system to test transmitting tubes, particuarly old surplus, NOS and Junquebox(EBAY) specials. - Original Message - From: W5OMR/Geoff [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 28, 2005 3:33 PM Subject: Re: [AMRadio] GG 813 Linear Rbethman wrote: I have the pages from the Radio Handbook for a GG 813 Amp, AND have the Email from W6SAI JUST prior to his becoming an SK to distribute it and place on my site. I'll put it back on the site if anyone wants it. Bob - N0DGN
Re: [AMRadio] Pi-Net vs Link Couple
The Pi-Net will give a total of 50 db suppresion of harmonics. about 20 in one spot and 30 in the other. Link couple can pass harmonics to VHF by capacity coupling, hence the Faraday Shield Links used for same later on. There is a nice single 450th Pi-Net rig shown in the Editor and Engineers handbook. Also a couple of single ended ones in the 1950 ARRL Handbook (for triodes). Some triodes that require lots and lots or drive can unbalance the grid tank, which is required for triodes using Pi-Net. Lo capacity tubes like the 450th is OK. The old timers mostly used tuners (antenna) and open wire feeders to keep the harmonics down. Hazletine link neutralization can also be used and no split tanks are needed in or out. Remember Class C , which is required for Hi level AM, is a extreme distortion and harmonic generator so that some plan need to be in place to handle the soup. Also a single band dipole is very frequency selective and cuts way down on harmonics by itself. Multiband dipoles, beams and multi dipole on one feeder and traps etc (G5RV) are an open invitation to spread gook with only link output. Also the guys that use CB lin years with no half wave filters get away in mobile service without too many problems due to the narrow frequency discrimination of mobile antennas. Hope this helps, 73 Mike - Original Message - From: Geoff [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 10:45 PM Subject: [AMRadio] Pi-Net vs Link Couple SO, here we are, well past 1991 and the 'law' that went into effect saying that 1,500w PEP output is the maximum RF Power output that we hams can run, regarldless of mode. That doesn't deter the homebrewing spirit, but it does suggest that acheiving 1,500w PEP output is much easier than producing 1kW DC input to the final. With the mindset of still wanting to use the classic high-level plate modulation scheme, engineering a rig to use only one tube in the final (a 4-250, 250TH, 304TH/TL, 4-400, etc), modulated by a pair seems to make more common sense. That, and it's a bit more economic in filament requirements. I've heard recently that matching the output of the Class C pate-modulated final to the antenna is better, and more efficiently achieved by link coupling, vs Pi-Net. On the other hand, it's argued that Pi-Net coupling produces less RFI than link coupling does. So, which is better? Why? What are the effects of nuetralizing a single tube in a balanced tank circuit? If Pi-Net is to be used, does the final tube still need to be nuetralized? I know of a guy who wants to build a rig using a single 450TL in the final, modulated by a pair. He wants to pi-net the output, but I've heard that's a bad idea. I want to build a rig using a medium powered tride, perhaps a 250TH, modulated by a pair of 811's. Pi-Net, or Link Couple? I like seeing this kind of technical discussion on the list. I'm looking forward to all inputs. -- 73 = Best Regards, -Geoff/W5OMR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Johnson 232-620
Correction: it is a 232-620. Paralax error reading handbook! - Original Message - From: Mike Dorworth,K4XM [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 10:48 PM Subject: [AMRadio] Johnson 232-620 Edgewise wound, 1/4 copper strip, cadmium plated, glass bonded mica supporting bars. Widely used commercially. Safely handles more that 1000 watts. 232-622 winding 8 5/16 Long, 4 ID. 84 Microhenry. __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Johnson 226-1
Johnson 226-3 Inductance 13.5 microHenry, 19.5 turns. Heavy duty rotary inductor for amateur and commercial use. Handle over a KW of modulated RF energy to 30 mHz. Winding 1/4 x 1/8 edgewise copper. Spring loaded beryllium copper contact. Variable pitch winding- wide frequency coverage. Height 6 1/2, width 4. Guaranteed to contain NO PCB's. - Original Message - From: Bob Maser [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 10:13 PM Subject: Re: [AMRadio] Johnson 226-1 My 226-3 is 14 uH and is good for a lot more goo that that. Bob W6TR - Original Message - From: Barrie Smith [EMAIL PROTECTED] To: Mike Dorworth, K4XM [EMAIL PROTECTED]; Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 9:56 PM Subject: Re: [AMRadio] Johnson 226-1 TNX, Mike - Original Message - From: Mike Dorworth,K4XM [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 7:37 PM Subject: Re: [AMRadio] Johnson 226-1 22.5 microhenry, 27 1/2 turns, 1 KW of modulated energy to 30 MHz. - Original Message - From: Barrie Smith [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 9:25 PM Subject: [AMRadio] Johnson 226-1 Hello All: Anyone have the specs on the Johnson 226-1 rotary inductor? Specifically need the total inductance. 73, Barrie, W7ALW __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
[AMRadio] Johnson 232-620
Edgewise wound, 1/4 copper strip, cadmium plated, glass bonded mica supporting bars. Widely used commercially. Safely handles more that 1000 watts. 232-622 winding 8 5/16 Long, 4 ID. 84 Microhenry. From [EMAIL PROTECTED] Wed Sep 21 23:06:30 2005 Return-Path: [EMAIL PROTECTED] X-Original-To: amradio@mailman.qth.net Delivered-To: amradio@mailman.qth.net Received: from surfmore.net (unknown [63.85.209.13]) by mailman.qth.net (Postfix) with ESMTP id B4FBA859C10 for amradio@mailman.qth.net; Wed, 21 Sep 2005 23:06:28 -0400 (EDT) Received: from default (maxdialup30.surfmore.net [:::65.218.183.30]) by surfmore.net with esmtp; Wed, 21 Sep 2005 21:51:06 -0500 id 0058C16F.43321C20.48E6 Message-ID: [EMAIL PROTECTED] From: crawfish [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net References: [EMAIL PROTECTED] Subject: Re: [AMRadio] Johnson 226-1 Date: Wed, 21 Sep 2005 22:00:06 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-BeenThere: amradio@mailman.qth.net X-Mailman-Version: 2.1.4 Precedence: list Reply-To: Discussion of AM Radio amradio@mailman.qth.net List-Id: Discussion of AM Radio amradio.mailman.qth.net List-Unsubscribe: http://mailman.qth.net/mailman/listinfo/amradio, mailto:[EMAIL PROTECTED] List-Archive: http://mailman.qth.net/mailman/private/amradio List-Post: mailto:amradio@mailman.qth.net List-Help: mailto:[EMAIL PROTECTED] List-Subscribe: http://mailman.qth.net/mailman/listinfo/amradio, mailto:[EMAIL PROTECTED] X-List-Received-Date: Thu, 22 Sep 2005 03:06:30 - If it was a power supply cap, they might have PCB's, but not an air inductor. Joe W4AAB - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, September 21, 2005 9:30 PM Subject: Re: [AMRadio] Johnson 226-1 If it was in a Viking I, it may well have PCBs in it. Be careful. 73, John, W4AWM __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
Re: [AMRadio] Drying out HV transformers / Chokes
Hey Joe, that's 140 degrees F without the thermostat being necessary!. Great Idea! - Original Message - From: Joe A. Taylor [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, September 18, 2005 2:09 PM Subject: Re: [AMRadio] Drying out HV transformers / Chokes I'm sure may be too simplistic to work but. why not put the xformer in the trunk of a car and leave it there, outside in the sun, for a week or month. Here in KY that works for most everything. I've dried apples this way ;-) Joe N4NAS Joe[EMAIL PROTECTED]
Re: [AMRadio] Thordarson 83d21 driver transformer
T-8321 Line to P.P. grids of 46, 210, Class B, etc. 500 ohms to 5100 , ratio1:3.2 . 2 lbs. also 500 to 12,5000 ohms, ratio 1:5. 3 inches high 2.5 inch wide 2.5 inches deep , mounting centers 2.7/8 inches. from Catralog #400 - Original Message - From: Mark Foltarz [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, September 04, 2005 2:46 PM Subject: [AMRadio] Thordarson 83d21 driver transformer Looking for specs on a 83d21 driver transformer. I think it is 500 ohm line to PP Grid. However, I am not sure. Hoping to drive a pair of 811s Tnx de KA4JVY Mark Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Re: Choke calculations
This was covered in QST for February 1963. page 16-17 The methode discussed uses a center tapped transformer and a full wave rectifier. The choke is placed in series with the resistor and the voltages are adjusted to be the same. The calculations are always at 120 Hz. It is not necessary for the voltages to be equal if a small amount of error is OK. The formula is XsubL equals Voltage across Reactor times the Resistance divided by the Resistor value. For 240 ma he uses 1250 ohm at 72 watts resistor and about 300 volts from a replacement xformer. Heavy overloads for a short time will not hurt the transformer. We have been here before. 73 Mike K4XM - Original Message - From: Patrick Jankowiak [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, August 21, 2005 6:12 PM Subject: [AMRadio] Re: Choke calculations Now THAT is the key to happiness! Since we might wish to also measure the inductance of a choke with some amount of DC current flowing through it, does anyone have an idea how to do this? In an example of a 10H choke, which would have 3768 ohms impedance, how would I pass 0.5 amp through it's 80 ohms of DC resistance without messing up the impedance measurement method? To me the obstacle looks like the issue of the power supply feeding the choke having a very low impedance compare to the measurement value to be made. Add to this the desire for a range of 0.1 to 100H and it's a real issue, at least from a calibration standpoint. I am certain some one on this list has done this before. It has to have been done in the choke factories of olden times! Patrick
Re: [AMRadio] power ratings
However, highly non-efficient. Actually not TRUE. The total power pulled from power supply determines effeciency. A low level and linear consumes less power for same carrier power. See some KW mobile rigs from years ago. also I remember WCKY had 50 watts modulated carrier ( 2 megawatts pep) and it was from a LINEAR!.. my$ 0.02. Mike
Re: [AMRadio] power ratings
You will get lots of answers. the short and correct answer is 100 watts carrier with peaks to 400 watts. I run a similar one at 150 watts carrier for short periods. The reason the ricebox drops to 25 watts is because it is 100 pep am under those conditions about 17 watts is what I use to drive my 3 x 811a amp here. There was a great article in QST explaining this and I have popsted ref in the past. The amp will easily do 600 pep but YOUR supply will not, Mine will. That is why they say 400 watts PEP.. Hope this helps.. mike - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, July 11, 2005 11:54 AM Subject: [AMRadio] power ratings I thought I understood these things, But I have confused me little self. I need some clear thinking here. I have a rice box rated for 100 watts SSB or 25 Watts AM. I believe the 100 watts is PEP while the 25 watts is RMS (continuous carrier). I want to add a linear amplifier to bring the 25 watts AM up considerably. I see the Ameritron AL-811 is rated for 600 watts SSB and 400 watts AM. Is this 400 watts PEP or RMS. If PEP that means the RMS rating is 100 watts, the same as my DX-100. Also it requires 75 watts of drive. Is this PEP or RMS. If RMS my rice box at 25 watts won't drive it. I am thinking the 75 watts of drive is PEP and my rice box with 100 watts PEP in AM will drive it. Can someone clarify this for me? Thanks. Ed K6UUZ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] cooking Baxter's goose
If any person fails to pay an assessment of a forfeiture penalty determined under subparagraph (A) of this paragraph, after it has become a final and unappealable order or after the appropriate court has entered final judgment in favor of the Commission, the Commission shall refer the matter to the Attorney General of the United States, who shall recover the amount assessed in any appropriate district court of the United States. In such action, the validity and appropriateness of the final order imposing the forfeiture penalty shall not be subject to review.
Re: [AMRadio] 117Z6GT question
This is normal. The cold resistance is always much less than normal. In a transmitting tube it is called in-rush. For the larger tubes some sort of protection is usually used, or at least a filament transformer no larger than necessary. The tube you are using has a 117 volt filament. 73 Mike - Original Message - From: gwt [EMAIL PROTECTED] To: AM Radio List amradio@mailman.qth.net Sent: Thursday, May 26, 2005 1:10 PM Subject: [AMRadio] 117Z6GT question I have a question for the list. I'm repairing an old am radio that uses at 117Z6GT as a rectifier. I have the radio working again, but I notice when I turn it on that the 117Z6 filaments glow really bright for a couple of seconds. Then settle down to what you would expect to see, a red glow. I don't have any experience with this tube, or how it should act at turn on. It what I'm seeing a normal condition? Thanks, George KE4HJ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] Thordarson-Meissner Chokes
From the Thordarson Catalog: Chokes, Universal Swinging and Smoothing T-20C51 5/25 MA15/35 Hy T-20C53 60/100 MA 8/17 Hy T-20C64 100/150 MA 3/7Hy T-20C55 150/300 MA 2/9Hy T-20C49 200/250 MA 4/5Hy T-20C56 250/375 MA 4/8 Hy From [EMAIL PROTECTED] Tue May 10 20:00:36 2005 Return-Path: [EMAIL PROTECTED] X-Original-To: AMRadio@mailman.qth.net Delivered-To: AMRadio@mailman.qth.net Received: from web50404.mail.yahoo.com (web50404.mail.yahoo.com [206.190.38.69]) by mailman.qth.net (Postfix) with SMTP id D5ABE859C06 for AMRadio@mailman.qth.net; Tue, 10 May 2005 20:00:33 -0400 (EDT) Received: (qmail 59900 invoked by uid 60001); 10 May 2005 23:52:39 - Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; b=guYMhru1yC8hin6nFmKnunIS6SUJOYKakTBzvkYwApXfa+JDe592Q8xfqQoTLZEWlKRfOfreB2xM6kFA+GYFNUi8toOKFu/MOMgXXXAv2xlhKjV9qyEh0YbaA+/2OFiDPpYBhySJdNY6Q6O+5XeL4swq0x06WyLqVstFo6l25lA ; Message-ID: [EMAIL PROTECTED] Received: from [216.255.39.190] by web50404.mail.yahoo.com via HTTP; Tue, 10 May 2005 16:52:39 PDT Date: Tue, 10 May 2005 16:52:39 -0700 (PDT) From: G. TAYLOR [EMAIL PROTECTED] To: AMRadio@mailman.qth.net MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Subject: [AMRadio] ARRL Bandwidth Regulation -- I'm Worried! X-BeenThere: amradio@mailman.qth.net X-Mailman-Version: 2.1.4 Precedence: list Reply-To: Discussion of AM Radio amradio@mailman.qth.net List-Id: Discussion of AM Radio amradio.mailman.qth.net List-Unsubscribe: http://mailman.qth.net/mailman/listinfo/amradio, mailto:[EMAIL PROTECTED] List-Archive: http://mailman.qth.net/mailman/private/amradio List-Post: mailto:amradio@mailman.qth.net List-Help: mailto:[EMAIL PROTECTED] List-Subscribe: http://mailman.qth.net/mailman/listinfo/amradio, mailto:[EMAIL PROTECTED] X-List-Received-Date: Wed, 11 May 2005 00:00:37 - I keep hearing from my section leader, and sure don't like what I'm getting! The FACT is that they want to re-regulate us, and provide for AM in a special exemption much as the KW grandfather clause. They then can just elimainate the exemption. To keep discussing the technical merits is a waste of time. They don't want the facts, they have there minds made up, and are only agreeable to amend them slightly to get it implemented. They then figure they can change it simply by taking out the exemptions! There is something BIG driving this, and I can't figure out what! I just recieved this from my section leader: -- Tentative proposals by frequency band: 160M - Entire band = up to 3 kHz 75/80M - Segments of up to 200 Hz, 500 Hz, and 3 kHz. A sub-segment of 3 kHz would be open to automatic control. AM and Independent SB (ISB) would be authorized by special exemption. 40M - Same as for 80/75. I read this as no exemption for 160M. Therfore NO AM. What can we do? We need to get together and get something started or we are going to lose big! Discussion of technical aspects, which they seem to ignore, will not help. We need somehow to present another face to the FCC or I'm afraid we will lose our operating privileges and can forget Ham Radio as we know it! I don't know how to do this, but hope we have an attorney or someone on this list who does. Sounds to me like we need to start a fund to fight this. Anybody got any ideas? I like my hobby. Don't want to give it up for automatically controlled digital operation!! Gary WB8BEM/8 __ Yahoo! Mail Mobile Take Yahoo! Mail with you! Check email on your mobile phone. http://mobile.yahoo.com/learn/mail
Re: [AMRadio] Hallicrafters SX-24 coil winding information
Without a GDO you can use a wavetrap on the Broadcast band. Put the circuit in the antenna and tune coil for null at low end of band with full cap. The ARRL L/C/F/ Calculator, formerly known as the Lightning Calculator calls for about 175 microhenry, on a three quarter inch form, it would take a winding length of 7/8 inch at about 145 turns per inch of no. 34. Hope this helps.. 73, Mike, K4XM - Original Message - From: Bill Fondren [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, April 18, 2005 12:10 PM Subject: [AMRadio] Hallicrafters SX-24 coil winding information I need help I have a old Hallicrafters SX-24 that the broadcast band coils, both osc and antenna coils are gone. For some reason the mice only got those 2 coils and the old set works pretty good on all the other bands so I would like to wind new coils and get the broadcast band working. My GDO does not have the BC band on it so its no help. I installed a universal osc coil that seem to work but I cant seem to get the ant coil right. I have used formulas on the web and get about the same number of turns for the windings. The coils are wound on 3/4 form, the tuning cap is 440 mmfd. with 4 mmfd of trim across it. I am using 34 gauge wire and the formulas I used says to use 130 turns for the secondary of the ant coil. I used about 50 turns for the input coil. Any help or suggections would be appreciated. I also have the HT-9 transmitter and would like to get the 1939 station back on the air. ThanksBill Fondren K5PML __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Fw: [AMRadio] BW 5100, 5100b differences?
The 5100B was plug and play with the 51SB-B Sideband Generator. I had one of each and the 6100 too! Best I remember that is the main difference. Mike K4XM -- Original Message -- From: George KB2Z [EMAIL PROTECTED] Reply-To: Discussion of AM Radio amradio@mailman.qth.net Date: Mon, 14 Mar 2005 09:30:35 -0500 Morning all, Could anyone on the list tell me the performance differences between the BW 5100 and 5100B? On the schematics the changes in the audio/modulator section jump out. Was one better than the other? Any thoughts or opinions would be appreciated. Thanks in advance, George KB2Z __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] need help with tranmitter design
heath called it linear master oscillator first used in the sb300 rx.. - Original Message - From: Jim candela [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Sunday, March 13, 2005 12:22 PM Subject: RE: [AMRadio] need help with tranmitter design Ed, One option would be to use a DDS VFO as your RF source, and drive the rig in 67 ARRL Handbook without modification. What do you intend to use as a receiver? Is this a tranceiver project? Also I cannot recall what LMO stands for? Maybe Local Modulated Oscillator? Some Google hits on LMO: Living Modified Organism Louisiana Radio Records Long Mountain Outfitters Little Marsh Overflow Life Maintenance Organization :-) Regards, Jim WD5JKO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Edward B Richards Sent: Friday, March 11, 2005 11:05 AM To: amradio@mailman.qth.net Subject: [AMRadio] need help with tranmitter design I am designing an AM, tube-type transmitter for mobile use. I want to use a minimum of parts to keep the cost, size, weight and power consumption to a minimum. Also, I want to use as many existing parts as possible. I have a Heathkit LMO for the VFO and a parts HW-101 for the tuning caps, coil etc. I found a circuit I like in the 1967 ARRL handbook, page 187 using only 4 tubes plus a VR tube. I need to modify the circuit to fit my wants. I am not engineer enough to redesign it. Can someone suggest a circuit to use a 12BE6 as a pentagrid converter using the oscillator section for a crystal oscillator with the LMO for the RF input. The output would be on final frequency. For 75/80 meters the crystal would be 9.00 mc. I would like to follow the mixer with a driver, then a 6146 final. It is screen grid modulated. I have all the tubes. Thanks. 73, Ed Richards K6UUZ AMI member #1534 __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.7.1 - Release Date: 3/9/2005 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.7.2 - Release Date: 3/11/2005 __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Info on SAIT HF amp?
well, I thought it was a Olds 442 from about 1966 or so. Four BBl carb, 4 on the floor and dual exhausts..442..would leave about the same dust as a pair of 4-400s would on 75M.. Mike - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, February 14, 2005 2:21 PM Subject: Re: [AMRadio] Info on SAIT HF amp? Pete wrote: as the 4-440A. Wasn't this an Oldsmobile muscle car?? -grin- yes, I must have been thinking of my old Plymouth Fury ex-state-police car with the 440 V8. Naturally the tube type should have been 4-400A Steve WD8DAS [EMAIL PROTECTED] http://www.qsl.net/wd8das --- Radio is your best entertainment value. --- __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.296 / Virus Database: 265.8.7 - Release Date: 2/10/2005
Re: [AMRadio] Scopes
the old Heathkit vector scope has a switch and leads that come directly from the plates, makes an instant scope for monitoring.. Mike - Original Message - From: Peter Markavage [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, January 13, 2005 2:22 AM Subject: Re: [AMRadio] Scopes Almost any old scope will work that doesn't billow smoke when you turn it on. Heath, Eico, Paco, a no name flea market treasure, and all the way to the whiz Tek and HP models. Some RF sampling into the vertical plates and you're in business. Pete, wa2cwa -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.6.11 - Release Date: 01/12/2005
Re: [AMRadio] Windom
Yup, thas rite! In or on a Windom, the idea is to find that spot where the antenna is resonant AND the feedline is attached to a piurely resistive point so that to SWR exists. This is the reason a properly made Windom has no feed line length restriction. The fact that it works as a resonant antenna with no feedline SWR is why we are still talking about it 75 years after Mr Windom worked out the formulas and a means of testing a multiband NO SWR antenna.. happy New Year! 73, Mike, K4XM - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Friday, December 31, 2004 8:03 AM Subject: [AMRadio] Windom Gents: Resonance, as I understand it, occurs when the capacitive and inductive reactances cancel. Regards, Steve WA2TAK __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.7 - Release Date: 12/30/2004 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.7 - Release Date: 12/30/2004
Re: [AMRadio] Windom
Boy are we down to the nity grity now!. Since one reactance is positive and the other negative that is leading and lagging or Eli the Ice Man so to speak, when they are added and the real componets are equal but the sines are opposite they CANCEL.. Happy New Year.. 73, Mike, K4XM - Original Message - From: Geoff/W5OMR [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Friday, December 31, 2004 8:35 AM Subject: Re: [AMRadio] Windom - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Friday, December 31, 2004 7:03 AM Subject: [AMRadio] Windom Gents: Resonance, as I understand it, occurs when the capacitive and inductive reactances cancel. not cancel .. 'are equal'. R = X(sub L)=X(sub C) or when Reactance is at, or very near 0 (Zero) Definition of Reactance: An ac circuit condition in which inductive and capacitive reactances interact to cause a minimum or maximum circuit impedance. www.yung-li.com.tw/EN/info/Glossary_list.htm 73 = Best Regards, -Geoff/W5OMR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.7 - Release Date: 12/30/2004 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.7 - Release Date: 12/30/2004
[AMRadio] Windom Antenna
In QST magazine for September 1929 the original Windom Antenna article starts on page 19. It clearly shows that it is exactly resonant on all of it's design bands, so long as there is an harmonic relationship. 80-40-20-10 etc. There are diagrams included which show how this is determined with an RF ammeter and a rolling trolley after which very precise and repeatable formulas were derived. Of course this is the single wire fed version. The later 300 Ohm job is merely wishful thinking.The length in feet is always 468, divided by desired frequency in Kc. For the lowest desired band. The tap is always feet times 25 divided by 180. I might add that antennas put up as temporary during this nasty winter weather last 20 to 30 times longer than summer installed permanent antennas. happy antenna experimenting. 73, K4XM, Mike. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.5 - Release Date: 12/26/2004
Re: [AMRadio] Windom Antenna
Okay, let us try again. I thought the question was.. how can it be RESONANT at more than one place..Mr. Windom clearly shows that it is and how to prove it. A antenna cut for twenty works great on 10, a forty meter job works great on twenty and ten, an 80 meter works 80-40-20-10 etc. It is always RESONANT on all harmonics.The single wire feeder shows about 600 ohms to ground and is worked against ground from the link or output. If the wire were fed in the center of the antenna, then the antenna WOULD NOT RADIATE at all, only acting as a top load capacitance. Also the length of the feeder is of no matter and 1200 feet works fine. Sure there is a little radiation from the feeder, but not too much. The straight away part insures that the RF picked up from the antenna (SORTA ) cancels out..These antennas work well with old Boat Anchor PI-Network outputs, those that go to 600 Ohms. There are no Standing waves on this type of antenna to feeder connection on the FEEDER!..I can e-mail the original QST article as an attachment (jPEG) for those wishing to read further on Mr. Windom's discovery.. Happy antenna experimenting in '05..73 de Mike, K4XM - Original Message - From: Geoff/W5OMR [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Monday, December 27, 2004 12:28 PM Subject: Re: [AMRadio] Windom Antenna In QST magazine for September 1929 the original Windom Antenna article starts on page 19. It clearly shows that it is exactly resonant on all of it's design bands, so long as there is an harmonic relationship. 80-40-20-10 etc. There are diagrams included which show how this is determined with an RF ammeter and a rolling trolley after which very precise and repeatable formulas were derived. Of course this is the single wire fed version. The later 300 Ohm job is merely wishful thinking.The length in feet is always 468, divided by desired frequency in Kc. For the lowest desired band. The tap is always feet times 25 divided by 180. I might add that antennas put up as temporary during this nasty winter weather last 20 to 30 times longer than summer installed permanent antennas. happy antenna experimenting. 73, K4XM, Mike. So, in order for this to work, you have to decide what frequency you're going to operate on, on the HIGHEST frequency the antenna will cover. ie: 29MC /2 = 14.5, 7.25, 3.625, 18.125Mc. that being the case, then L = 468/f(L) L = 468/18.125 L = 258.20689655172413793103448275862 Now, you said that the 'tap is always feet times 25 divided by 180' T = 258.207ft * 25 / 180 T = 6455.17 / 180 T = 35.862068965517241379310344827586 Single wire feeding it? Fed against Ground? Doesn't the single feed-line then become part of the radiating antenna? Even if someone were to take, say the output of a link and feed it directly to the open wire feed-line, the open wire line would have to go all the way to the feed point of the antenna, wouldn't it? I'm sorry if I'm seeming a little dense, but I can't get unwrapped from the 'single wire fed version' of this antenna. Open wire output from the link has *2* wires. I can see attaching them to some open wire line, and feeding this Wyndom antenna at 1.8125, and having the antenna resonant on 3.6250, 7.250, 14.5 (oops - can't operate there) and 29Mc, but I simply fail to understand how one wire is going to feed an antenna thas has two posts to connect to. Certainly has me thinking, though. Now, if I could just come up with land that had 300' (for guy supports on both sides) I'll have to work CW on 3.6250, forget about 20m and enjoy a multi-wavelength antenna on 10m (when the band is open). Pardon the sarcasm ;-) Seriously, here. Surely, there must be something I'm missing, to be able to use this antenna on all bands, with acceptable VSWR. 'Splain it to me, please. Happy New Year 73 = Best Regards, -Geoff/W5OMR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.5 - Release Date: 12/26/2004 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.5 - Release Date: 12/26/2004
Re: [AMRadio] Lowest level modulation
With the laws now reading that 1500w PEP OUTPUT is the power limit, regardless of mode, why not run 1500w Output of FM, at +/-5kc? ;-) Narrow band FM has always been allowed.. I take this to be 3 or 6 kc. The wider band stuff is for above 29 mcs. I guess my old rule book is out of dade, the original question was about amplitude modulating an oscillator. It was earlier strictly forbidden. Looks like a rewirte has changed it to good enginnering practice! Ask Mr Zack Lau, simply Is it good enginering practice to modulatate an oscillator for AM. If you really wanna do it then there is a dandy 6V6, 813 rig in the RCA tube handbook for 1942 using a single modulated B+source for all HV functions and the 6V6 tube drop for the screen supply. This will give you the TimTron Crappy SBE signal you desire.. Again 73 and MERRY CHRISTMAS to all like minded Belivers.. Mike K4XM Original Message - From: Geoff/W5OMR [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Thursday, December 23, 2004 3:18 AM Subject: Re: [AMRadio] Lowest level modulation - Original Message - From: Mike Dorworth, K4XM [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Wednesday, December 22, 2004 8:00 PM Subject: Re: [AMRadio] Lowest level modulation Hi , it is illegal to use a modulated oscillator below about 2 meters. It will work but adds FM even to a crystal oscillator. In fact commercial vhf equipment using crystals actually phase modulate the crystal oscillator to get FM. They of course go through several multiplications to get the plus and minus 5 kc deviation.. That's kHz for youngsters!.. The rules simply state NO!..hope this helps.. Mike K4XM You might want to check again, Mike... 10m FM is pretty popular. As I recall, the rules state that FM is allowed on HF as long as it's no wider than a conventional AM signal. That said, if these modern day rice-boxes have FM on 'em, I wonder how difficult it would be to check the deviation and modulation index on said rigs, to keep 'em down to 2.5kc of deviation? With the laws now reading that 1500w PEP OUTPUT is the power limit, regardless of mode, why not run 1500w Output of FM, at +/-5kc? ;-) 73 = Best Regards, -Geoff/W5OMR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.4 - Release Date: 12/22/2004 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.4 - Release Date: 12/22/2004
[AMRadio] §97.307 Emission standards.
§97.307 Emission standards. (a) No amateur station transmission shall occupy more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice. (b) Emissions resulting from modulation must be confined to the band or segment available to the control operator. Emissions outside the necessary bandwidth must not cause splatter or keyclick interference to operations on adjacent frequencies. (c) All spurious emissions from a station transmitter must be reduced to the greatest extent practicable. If any spurious emission, including chassis or power line radiation, causes harmful interference to the reception of another radio station, the licensee of the interfering amateur station is required to take steps to eliminate the interference, in accordance with good engineering practice. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.298 / Virus Database: 265.6.4 - Release Date: 12/22/2004
Re: [AMRadio] AM Usage with Linear AMPS
QST for February 1956 in the Technical Topics section has a nice three page write up on the use of Linear Amplifiers for AM. It starts on page 39. This leads to the rule of thumb that on a.m. the carrier power output that can be obtained from a linear amplifier is equal to half the rated dissipation of the tube(s).
Re: [AMRadio] smelly oil in the Electro Manufacturing modulationtransformer
If it was made anytime prior to the early 1970's then it is Dektol, Pyronal or other trade names for PCBs. The bad stuff. Don't drink it! Mike - Original Message - From: Mark Foltarz [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, November 04, 2004 9:21 PM Subject: [AMRadio] smelly oil in the Electro Manufacturing modulationtransformer Hello Group, I was organizing the storage area today. The last thing I moved was the mod transformer for the 5 KW gates parts unit. Well one of the insulators has a bad seal and it leaks oil from the transformer. Man! does it smell weird - like a thousand times worse than the old mimeograph machines did. I have to fix it or dump it. I think I'll fix it by sealing up the insulators. But what is that oil? tnx DE KA4JVY Mark __ Do you Yahoo!? Check out the new Yahoo! Front Page. www.yahoo.com __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Surge suppressors
The power companies here in Georgia install and charge by the month..but you have purchased 100 percent coverage on anything damaged by any surge that comes down the line..not such a bad deal.. Mike K4XM - Original Message - From: Jim Wilhite [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Tuesday, September 21, 2004 4:01 PM Subject: [AMRadio] Surge suppressors I am wondering if any of you have installed a whole house surge suppressor? I contacted my electric supplier, but they charge an on-going fee for theirs. If you have one installed, what brand and model did you use? 73 Jim de W5JO __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Johnson Match Antenna tuner
[EMAIL PROTECTED] wrote: What is the proper adjusting procedure for using a Johnson Matchbox ant tuner..There are two controls..tuning and Matching...Which is adjusted first? tnx ..Well her is my $0.02 worth. Since I have owned 6, 2 bigs, 4 littles and used them for years I will add this little bit of information. The Left knob resonates the circuit, the right knob is a dual, dual differential which in theory should never change it's capacity. Actually it does not work quite like the idea calls for. It's job is to provide a potentiometer effect that would be the same as tapping the antenna on the coil turn by turn from the high impedance to low impedance end of the standard parallel tuned circuit. In practice, the turning of one sorta effects the other plus the fact the input link is fixed and stuff is reflecting every where. The main idea is to get the reflected power to zero, the old time highly frequency sensitive swr bridge makes it a hard job to say the least. Since a watt or two can make it look like everything is being reflected. I find that the easy way is to use a modern toroid based wattmeter and twiddle knobs for minimum reflected power without regard for output power, then I tune on all bands of interest and make the settings on the provided charts. If one band is tricky or flaky, I change the feedline length until it loads smoothly on all bands. I have never found an antenna that can not be tuned by the Johnson after adding or subtracting some feed line. You start with the notion it WILL WORK and then you make it so. Also if you are using a boat anchor, hmnn, don't we all? Then the rig must be tuned to a dummy and left alone and the matchbox tuned. If the rig is not tuned first and you get to twiddling knobs it will be most frustrating.. Hope this helps.. 73 Mike K4XM --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.734 / Virus Database: 488 - Release Date: 8/4/2004
Re: [AMRadio] Special email
Clark Howard covered this yesterday. The bank will say the check is OK, IT AIN'T, you WILL LOSE YOUR MONEY! - Original Message - From: David Knepper [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Tuesday, July 13, 2004 12:42 PM Subject: [AMRadio] Special email Has anyone heard of a scam where a person supposedily has a check from someone in the States that owes him money and he wants you to cash this check and take out the money for the radio. You then send him the differerence to him. Sounds like a scam to me. I thought I had read about this scheme somewhere. A quick reply will be appreciated. Thank you Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.719 / Virus Database: 475 - Release Date: 7/12/04
Re: [AMRadio] Tower Construction
Don't know what book says. Been under impression for 40 years or more they were free standing (25G) up to 60 feet especially with a house bracket. I put one up at 55 ft in 1981, self supported with tri-bander, it is still here! and we have had several really high wind attacks, a nasty ice storm.. My book says no more than 60 feet without guys while constructing. The 135 footer I put up in 1965 had guys 60, 90, 120 feet.. it is still there! Don't know.. go figure! Mike K4XM I am contemplating placing a 10 foot section of Rohn 55G halfway in a cement base. Could someone suggest how many section could I add if the tower were self-supporting. Any suggestions would be appreciated. Thank you Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.705 / Virus Database: 461 - Release Date: 6/12/2004
Re: [AMRadio] Chassis Wanted
These are in stock at Mouser and Antique Radio Supply (tubes more). I got one from Mouser this size that was dropped shipped from Canada..came in 2 days.. 73 Mike - Original Message - From: Merz Donald S [EMAIL PROTECTED] To: 'Amradio (E-mail) amradio@mailman.qth.net; 'Baswaplist' (E-mail) [EMAIL PROTECTED]; 'Glowbugs (E-mail) [EMAIL PROTECTED] Sent: Tuesday, April 06, 2004 12:00 PM Subject: [AMRadio] Chassis Wanted Hi. I'm looking for a chassis for a project. It should be female, about 27 years old with size 38Coh wait...wrong list... Actually, I need a 17 L x 11 W black wrinkle painted steel or aluminum chassis for a project. The dimensions are fixed to fit into an existing homebrew rack. So I need these exact dimensions. Chassis depth should be 2.5 or more. It can have holes but should not be completely Swiss cheese. I will buy something that has the remains of an old project on it and clean it off if need be. Whatever... Trade glowbug parts or ham gear parts or tubes or pay cash. Any references to a source for this item would be much appreciated. This is one of those cases where I have just about every other size--but of course, not the one I need. Thanks. 73, Don Merz, N3RHT The information contained in this e-mail may be confidential and is intended solely for the use of the named addressee. Access, copying or re-use of the e-mail or any information contained therein by any other person is not authorized. If you are not the intended recipient please notify us immediately by returning the e-mail to the originator.(A) ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] ART-13 conversion
In one of the older Editors and Engineers handbook about the 13th I think is a modulator built from the audio parts, complete speech amp, pair 811's and ART-13 modulation transformer. 110 watts to secondary of transformer. Lots of single 813 finals from this time frame could be built with the RF stuff. With some skillful hacksawing the final capacitor can be made a remountable cap. (I have two!). ART-13s are pretty tough, should still work, even if a bulldozier ran over it! LOL..Mike K4XM - Original Message - From: Mahlon Haunschild [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, March 22, 2004 8:24 PM Subject: [AMRadio] ART-13 conversion Hello, list. Are there any examples out there of an ART-13 conversion (or maybe repackaging) to make something more operator-friendly or cabinet-friendly? Reason being I acquired a basket-case ART-13 last week that I would never dream would work in its original form (too filthy/bug-eaten), so gutting the cabinet, getting rid of all of the auto-tune stuff, but keeping the RF / audio hardware and re-packaging the result to build something in a rack-mountable format came to mind. Didn't get a power supply, so that's a whole 'nuther discussion, of course. Opinions? Rotten tomatoes? regards, Mahlon - K4OQ ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Re: SX-28 help
Hello to the list. Feel like I should offer my $0.02 worth here. Many old receivers such as my SX-17F and the SX-28 were designed for 110 volts AC. Lots of us have 120 up to 125 volts in the houses built in last 30-40 years which means more volts. More volts everywhere. Add to this that it is real easy to solder a couple of solid state diode accross the 5Z3 socket and all of a sudden you have 470 volts of B plus. A 6L6 is speced at maximum 360 volts!. Especially if you decide to use 40, to 100 mfd capacitors in place of the old wimpy 8 mFds used in the old stuff. One solution is the Variac or 500 to 800 ohms resistance in series with the filter choke. All that said, 6F6, 6V6, 6L6, metal tubes all, can get pretty warm running at rated input which means that the vent holes provided on cabinets of these old beasts must not be blocked by being pushed next to and under several hundred pounds of other boat anchors. Happy New Year to all, and 73. Mike K4XM From: w5sum [EMAIL PROTECTED] To: amradio@mailman.qth.net Date: Mon, 29 Dec 2003 11:34:18 -0500 Subject: [AMRadio] SX-28 help Reply-To: amradio@mailman.qth.net I had a parts unit here so I took the audio transformer out of it,and put it in the one I'm restoring. I wired the headphone jack up correctly, and the speaker jacks on back. I now have decent audio from the speaker terminals with the factory speaker, and so so audio using a 8ohm headset at the headphone jack. HOWEVER, the 6L6's ( someone subbed out the 6V6's ) run scalding hot.. I mean.. so hot you can smell them. I have changed EVERY component in the audio section around the output tubes, and the 6SC7. Anyone have any solutions to why these tubes are getting so hot? thanks in advance ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.554 / Virus Database: 346 - Release Date: 12/20/2003
[AMRadio] 4d32 specs from NJ7P
4D32 Beam Power Pentode Characteristics Heater or Filament Voltage . 6.3 volts Heater or Filament Current . 3.75 amperes EIA Base . . . . . . . . . . F26 Prefered Substitutes . . . . None Substitutes. . . . . . . . . None For Characteristics and Typical Operation, See 4D22 Capacitances and Design Maximum Values Section. . . . . . . . . Pentode Cin. . . . . . . . . . . . 28 pf Cout . . . . . . . . . . . 13 pf Cgp. . . . . . . . . . . . 0.27 pf Plate Dissipation. . . . . 50 watts Screen Dissipation . . . . 14 watts Maximum Plate Voltage. . . 750 volts Maximum Screen Voltage . . 350 volts Full Frequency . . . . . . 60 MHz 4D22 Beam Power Pentode Characteristics Heater or Filament Voltage . 12.6/25.2 volts Heater or Filament Current . 1.6/0.8 amperes EIA Base . . . . . . . . . . F26 Prefered Substitutes . . . . None Substitutes. . . . . . . . . None Capacitances and Design Maximum Values Section. . . . . . . . . Pentode Cin. . . . . . . . . . . . 28 pf Cout . . . . . . . . . . . 13 pf Cgp. . . . . . . . . . . . 0.27 pf Plate Dissipation. . . . . 50 watts Screen Dissipation . . . . 14 watts Maximum Plate Voltage. . . 750 volts Maximum Screen Voltage . . 350 volts Full Frequency . . . . . . 60 MHz Typical Operation as a Transmitting Tube Class of Service VpVsVsup Vg Ip Is Ig DriveZlPo Class C Amp 750 300 - -100 240 26 12 1.5 - 135 Class C Amp 600 300 - -100 215 30 10 1.25 - 100 Class C Mod Amp (Plate) 600 - - -100 220 28 10 1.25 - 100 Class C Mod Amp (Plate) 550 - - -100 175 176 0.6 -70 PP Class AB2 Amp 600 250 - -25 100 26- 0.453K 125
