Re: [AMRadio] power ratings
Didn't this subject get beat to death back in January of this year? Dennis D. W7QHO Glendale, CA
Re: [AMRadio] power ratings
Geoff wrote: Donald Chester wrote: The plate dissipation of the 6146's is the key. Your carrier steady on should not exceed the dissipation rating. This is about 50 watts if I remember right which would give you 200 watts PEP. So your power suppl;y should be capable of about 150 watts continuous and it will handle the 200 watts on peaks. I would beef up the fan so that I had a good amount of air passing the glass of the 6146's to keep the seals cool. In AM linear service, the carrier output should not exceed HALF the total plate dissipation. A 6146 runs about 25 watts plate dissipation, so with a pair of them, you should be able to run 25 watts out. With 100% modulation in the positive direction, that would be 100 watts pep. A properly functioning AM final capable of 100% modulation should run about 33% carrier efficiency. That means that two-thirds of the input power is dissipated in the plates of the final, and one third is delivered as rf output. When the carrier is modulated, the final actually becomes more efficient, so the plate dissipation is reduced under modulated conditions. The DC input should not vary, so that simply means that some of the DC input that was being dissipated as heat is now being converted to rf output in the form of sideband power. Is that where sideband energy then is created and therefore exists as long as there's a modulate AM carrier? I wasn't in on the big discussion about this, a few months ago. --- 73 = Best Regards, -Geoff/W5OMR The side band power is created in the low level modulated stage and amplified by the linear amp just like the carrier. However, the total amplifier power operates on the composite signal and not individually on each component of the signal. The composite signal looks like one signal to the amplifier. With modulation present the amplifier is operating at a better plate impedance match to the load at that power level. With modulation peaks it is operating at the load point where it was tuned to, its most efficient point. So as modulation increases the load point of the (properly tuned) amplifier has a better match and delivers more power out at that higher power level (modulation peaks). The efficiency of the amplifier increases as load point is approached. You can readily see how the efficiency changes with power level by varying the carrier drive level (no modulation) and calculating input power verses output power at different drive levels. For more insight look at "efficiency modulation" in some of the handbooks. 73 Gary K4FMX
Re: [AMRadio] power ratings
Gary Schafer wrote: Geoff wrote: Gary Schafer wrote: The best quality audio of all can be gotten from low level modulation and a linear amplifier. However, highly non-efficient. Efficiency doesn't matter anymore for hams. Output power is the limiting factor not input power. I don't operate in those circles. I'm still a ham from the OLD days, when Radio was RADIO. For what some pass off as hams these days, you could do just as well to drive down to the local discount store, and buy a boom-box and plug it in. That's all it takes to be a ham these days, anyway - right? No one builds anymore. It seems like no one goes out and finds some wire, stretches out a pre-determined length and feed a peice of coax in the middle of it, to make an antenna. No, they'd rather BUY a dipole... HOLY JIMMINY! The first "commercial dipole" I saw for sale, I about soiled my knickers. I thought "now, there's a guy with a good idea, but who's gonna pay $50 for 25' of RG-58 coax, a pair of connectors, some copper wire and a peice of pvc? That was at a hamfest, and an hour later, he was sold out. Ain't for me, man... --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] FS: Heath Manuals, E-200-C, etc.
I would like the WA-P2 manual if still available. Paul - Original Message - From: "Jim Candela" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 11:27 AM Subject: Re: [AMRadio] FS: Heath Manuals, E-200-C, etc. > Don, I'm interested in the Megohmeter. Let me know > with shipping to 78681. > > Jim > > --- Merz Donald S <[EMAIL PROTECTED]> wrote: > > > For Sale: Heathkit Manuals, E-200-C, etc. > > > > Precision E-200-C Signal Generator. Nice looking > > shape in every respect. Leather handle intact. $19 > > > > Military AN/PSM-2 ZM-14A Megohmeter with snap-on > > lid. Cool meter for 0-1000 meghohms with built-in > > hand-crank generator for test voltage. $19 > > > > Heathkit Original Manuals. Most of these have the > > oversize fold-out drawings. $6 each, 2 for $10. $1 > > each for US media mailing. > > > > AA-1 Audio Analyzer > > AG-10 Sine-Square Wave Generator > > CB-1 Citizens Band Transceiver > > HD-1 Harmonic Distortion Meter > > IB-2A Impedance Bridge > > IT-21 Tube Checker with a bunch of supplemental test > > data charts > > LG-1 Laboratory Type Signal Generator > > PS-4 Regulated Power Supply > > QM-1 Q-Meter > > WA-P2 Preamplifier > > > > Hazeltime Electronics Corporation 500V 200ma power > > supply. This is in a beat up 15x9x11 black wrinkle > > steel cabinet with flip-top lid. Both volts and MA > > are metered. Output is variable using a variac that > > looks cooked. Filament voltage is also adjustable. > > Output is taken at binding posts on front. Navy UTS > > anchor symbols are stamped in several places. > > Components and construction are first rate. > > Rectifier tube is a 5U4 which seems over-worked in > > this application to me. 2 big Thordarson chokes in > > output filter. Front panel labeling must've been > > done by the student intern because it is sloppy. > > Minus the variac, this would need very little to be > > an excellent, fixed-output transmitter power supply. > > Untested. As-is. $30. Heavy-will cost more to ship > > than to buy. > > > > Thanks for looking. > > 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.(17b) > > > __ > > 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 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] power ratings
Geoff wrote: Gary Schafer wrote: The best quality audio of all can be gotten from low level modulation and a linear amplifier. 73 Gary K4FMX However, highly non-efficient. --- 73 = Best Regards, -Geoff/W5OMR Efficiency doesn't matter anymore for hams. Output power is the limiting factor not input power. 73 Gary K4FMX
Re: [AMRadio] power ratings
kenw2dtc wrote: "But if you want broadcast quality audio you need a real plate modulated rig" "The best quality audio of all can be gotten from low level modulation and a linear amplifier." ***I disagree with both statements above. If properly set up and fixed with the proper audio chain, a plate modulated rig, a broadcast transmitter, a rice box and linear, a plate modulated rig and a linear or a class "E" rig could sound like "broadcast quality" and the listener would not be able to distinguish the difference. 73, Ken W2DTC But the difference could be measured. 73 Gary K4FMX
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
"But if you want broadcast quality audio you need a real plate modulated rig" "The best quality audio of all can be gotten from low level modulation and a linear amplifier." ***I disagree with both statements above. If properly set up and fixed with the proper audio chain, a plate modulated rig, a broadcast transmitter, a rice box and linear, a plate modulated rig and a linear or a class "E" rig could sound like "broadcast quality" and the listener would not be able to distinguish the difference. 73, Ken W2DTC
Re: [AMRadio] power ratings
Gary Schafer wrote: The best quality audio of all can be gotten from low level modulation and a linear amplifier. 73 Gary K4FMX However, highly non-efficient. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] power ratings
The best quality audio of all can be gotten from low level modulation and a linear amplifier. 73 Gary K4FMX Bob Macklin wrote: A comment about AM transmitters. A plate modulated AM transmitter requires a modulator of 50% of the power of the final to produce 100% modulation. These transmitters like the Johnson Ranger produce better audo than the screen modulation units like the small Heaths. Only the Heath DX-100 and TX-1 (Apachee) used plate modulation. But most of the airborne military transmitters used screen modulation to reduce the weight and power requirment. These all produce very good comunication audio. But if you want broadcast quality audio you need a real plate modulated rig. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "kenw2dtc" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 5:30 PM Subject: Re: [AMRadio] power ratings "Ken, as I read the rules, we are only allowed to run 375 watts carrier. With 100% modulation this will give us 1500 watts pep which is the max output allowed." ***Don, You are correct about the 1500 watts PEP. It could also be derived by 600 watts of carrier with much less than 100% modulation. There are also schemes where the carrier is almost 1000 watts and it is modulated downward at nearly 100% and still get the 1500 watts PEP. Another comment about linears in AM service. Those who do the math and run an SSB linear with the PEP equal to 4 times the carrier sometimes miss the calculation of the male voice which will usually modulate higher than 100% unless limited in the audio section. Thus many SSB amps do not have the headroom for good AM. __ 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 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] power ratings
A comment about AM transmitters. A plate modulated AM transmitter requires a modulator of 50% of the power of the final to produce 100% modulation. These transmitters like the Johnson Ranger produce better audo than the screen modulation units like the small Heaths. Only the Heath DX-100 and TX-1 (Apachee) used plate modulation. But most of the airborne military transmitters used screen modulation to reduce the weight and power requirment. These all produce very good comunication audio. But if you want broadcast quality audio you need a real plate modulated rig. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "kenw2dtc" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 5:30 PM Subject: Re: [AMRadio] power ratings > "Ken, as I read the rules, we are only allowed to run 375 watts carrier. > With 100% modulation this will give us 1500 watts pep which is the max > output allowed." > > ***Don, You are correct about the 1500 watts PEP. It could also be > derived by 600 watts of carrier with much less than 100% modulation. There > are also schemes where the carrier is almost 1000 watts and it is modulated > downward at nearly 100% and still get the 1500 watts PEP. Another comment > about linears in AM service. Those who do the math and run an SSB linear > with the PEP equal to 4 times the carrier sometimes miss the calculation of > the male voice which will usually modulate higher than 100% unless limited > in the audio section. Thus many SSB amps do not have the headroom for good > AM. > > > > > > > > __ > 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] power ratings
"Ken, as I read the rules, we are only allowed to run 375 watts carrier. With 100% modulation this will give us 1500 watts pep which is the max output allowed." ***Don, You are correct about the 1500 watts PEP. It could also be derived by 600 watts of carrier with much less than 100% modulation. There are also schemes where the carrier is almost 1000 watts and it is modulated downward at nearly 100% and still get the 1500 watts PEP. Another comment about linears in AM service. Those who do the math and run an SSB linear with the PEP equal to 4 times the carrier sometimes miss the calculation of the male voice which will usually modulate higher than 100% unless limited in the audio section. Thus many SSB amps do not have the headroom for good AM.
Re: [AMRadio] power ratings
In fact, since many people refuse (or just don't know how) to click on a
link, allow me to paste some of that here, that is germane to the
overall discussion of power levels, ratings, and class of operation of a
tube.
-Geoff/W5OMR
=
Amplitude Modulation ("AM")
using natural asymmetrical voice
a joint effort by
John, WA5BXO
Bob, WA3WDR (Bacon)
Tim, W5TOB
Don, K4KYV
When I (John) first tried AM, I had a Knight Kit T-60 transmitter, which
used controlled-carrier modulation. Controlled-carrier modulation is a
method of modulation that maintains a low carrier output until
modulation is applied, and then the carrier will increase with the
average level of modulation. This is done to keep the power consumption
and heat low when you are not modulating. It was often used in rigs that
were inexpensive and had components that were not sturdy enough to
maintain a higher level of carrier and modulation. Modulation was
accomplished by applying audio voltage to the screen grid bias voltage
of the RF output tube. Controlled-carrier operation resulted from
deliberate rectification of the audio waveform in sections of the
modulator that were DC-coupled to the modulator output, and this was
arranged to cause the average screen bias voltage to shift upward when
audio was present, thereby increasing the carrier level when modulation
was present. If this system was not overdriven, the resulting signal was
readable, although not pleasing to the listener. The diode detector type
receiver's AGC voltage would bump up and down with the carrier shift.
This caused a very annoying rise and fall of background noise. Also,
with loud speech, the rectifying section of the modulator could easily
overperform its function. The resulting distortion was so severe that
most of the audio was actually eliminated, just when it should have been
the loudest! It was very difficult to avoid overdriving the modulator,
without the modulation being too low to hear well. The group of hams
that I wanted to join on 3850 KC just couldn’t hear me, or complained
endlessly about the awful sound from my rig’s controlled carrier
modulation.
Their complaints were constructive, and they convinced me that I needed
to upgrade my modulation technique if I was going to join in the AM fun.
My solution was to build a plate modulation system. The modulating audio
voltage was derived from an external audio amplifier that could deliver
the proper audio voltage to the plate supply circuit of the final RF
amplifier. The improvement this made in signal output and audio quality
was remarkable. The group could hear me, and hear me clearly. Over time,
I learned more, but the knowledge came slowly. It was almost 10 years
before I really understood the circuit, and the math behind it. A lot of
this understanding is due to my association with Don, K4KYV.
The T-60 was typical of many relatively low-cost transmitters available
to newcomers to the hobby in the years from 1960-65, and it is an
example of how the manufactures were trying to sell equipment. The
advertisements would say something like “Here is a transmitter that will
run near the legal limit for a novice on CW and has the capability of
running AM when the novice upgrades to general class.” The Knight Kit
T-60 rig described above was purchased for about $70. The cost of adding
the AM capability to the transmitters design was probably about $5. The
external modulator that I constructed was built from scrap and
hand-me-down parts, but had the parts been purchased, they would have
cost more than the Knight Kit T-60. The original $5 modulator that was
put into the Knight Kit T-60 was a bungled attempt to add AM capability
to a low-cost transmitter, but it sold a lot of transmitters.
Why was screen modulation used? Because it was inexpensive and simple.
It did not require any transformers, and only small, low power tubes
were needed in the modulator.
Why was controlled-carrier modulation used? Mostly to reduce RF
amplifier plate dissipation. Efficiency is low in a screen-modulated AM
transmitter. Typical carrier efficiency is only about 35%. The typical
6146B could only produce about 15 watts of carrier power, and at 35%
efficiency the plate dissipation was about 28 watts. The thought was to
reduce plate dissipation when no audio was present, by reducing the
carrier output. Efficiency was lower at lower output levels, but
dissipation was lower, too. The idea was that average plate dissipation
would be lower, so more carrier power could be produced when audio was
present, without overheating the tube. However, the transmitter designs
really did not produce much more usable carrier power during modulation,
and distortion was so bad that this power seemed higher, but it really
did little good.
Some amateurs have made simple improvements to the screen modulator
circuitry of the T-60 and similar r
Re: [AMRadio] power ratings
Rev. Don Sanders wrote: Ken, as I read the rules, we are only allowed to run 375 watts carrier. this is wrong. There is -no- maximum carrier limit. The only maximum power limit imposed on Ham Radio operators is 1,500W PEP output, regardless of mode. 1,500W PEP output on AM, -would- be 375w *if* you modulate that carrier with a sine-wave. We don't talk in sine-waves. Don Chester/K4KYV, Bacon/WA3WDR and John Coleman/WA5BXO collaborated on this very subject. ALL AM'ers should read this page, and read it again and when you're done, read it again. www.qsl.net/wa5bxo/asyam/aam3.html 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] Valiant doorknob cap
On Tue, 12 Jul 2005, Bob Maser wrote: I would not change it because doorknobs aren't susceptible to age. Shows 420 pF on an LCD cap meter - Sprague Tel-Ohmike (at 600V) shows 220 pF. Cross-testing other (similar) caps shows a very small variation in readings. Someday when I'm rich I'll buy an ESR meter that goes down into the pFs and that'll tell for sure - but the Tel-Ohmike is consistently within 4 or 5% of it's readings when using known-quantity devices, so I think the doorknob needs a little Graphite Thanks! Cheers John KB6SCO
Re: [AMRadio] power ratings
Ken, as I read the rules, we are only allowed to run 375 watts carrier. With 100% modulation this will give us 1500 watts pep which is the max output allowed. I agree 300 watts carrier is almost necessary, however smaller linears wont handle that and if funds are limited, 150 watts with 600 pep isw better than nothing. I use my DX60B into the SB200 and the controlled carrier helps to keep the plate dissapation low on the 572B's. Healthfully yours, DON W4BWS - Original Message - From: "kenw2dtc" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 2:39 PM Subject: Re: [AMRadio] power ratings > I've been using linear amps in AM service for a few year now. With current > band conditions, it seems to me that a goal should be at least 300 watts of > carrier. Sure you can make contacts with 25-50 watts but for consistant > contacts, the higher power is the best. When guys ask me about linears, I > usually advise that they shouldn't waste time on any linear with a tube or > tubes with less than 1000 watts of plate dissapation. One of the best off > the shelf amps is the Ameritron AL-1200 and even with that amp, when I reach > 1500 watts PEP on AM the scope will start to show flattopping above that > level. In addition, the smaller off the shelf SSB amps do not have the > necessary beefy power supply to do AM operations at the rated PEP ratings. > 73, > Ken W2DTC > > __ > 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] Valiant doorknob cap
I would not change it because doorknobs aren't susceptible to age. Bob - Original Message - From: "John Lawson" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 4:28 PM Subject: [AMRadio] Valiant doorknob cap Anyone have a (better??) replacement for the doorknob cap in the tank circuit of a Valiant? I'm doing an overall re-cap prior to getting on the AM air - I can order a capacitor that exceeds the specs, but there is the structural question in that the doorknob is also a spacer. It's 500 pf at 10 - 20 KV IIRC... Lemme know ASAP if yo've got something you'd like to sell... Cheerz Jhn 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
[AMRadio] Valiant doorknob cap
Anyone have a (better??) replacement for the doorknob cap in the tank circuit of a Valiant? I'm doing an overall re-cap prior to getting on the AM air - I can order a capacitor that exceeds the specs, but there is the structural question in that the doorknob is also a spacer. It's 500 pf at 10 - 20 KV IIRC... Lemme know ASAP if yo've got something you'd like to sell... Cheerz Jhn KB6SCO
Re: [AMRadio] power ratings
I've been using linear amps in AM service for a few year now. With current band conditions, it seems to me that a goal should be at least 300 watts of carrier. Sure you can make contacts with 25-50 watts but for consistant contacts, the higher power is the best. When guys ask me about linears, I usually advise that they shouldn't waste time on any linear with a tube or tubes with less than 1000 watts of plate dissapation. One of the best off the shelf amps is the Ameritron AL-1200 and even with that amp, when I reach 1500 watts PEP on AM the scope will start to show flattopping above that level. In addition, the smaller off the shelf SSB amps do not have the necessary beefy power supply to do AM operations at the rated PEP ratings. 73, Ken W2DTC
Re: [AMRadio] power ratings
Donald Chester wrote: The plate dissipation of the 6146's is the key. Your carrier steady on should not exceed the dissipation rating. This is about 50 watts if I remember right which would give you 200 watts PEP. So your power suppl;y should be capable of about 150 watts continuous and it will handle the 200 watts on peaks. I would beef up the fan so that I had a good amount of air passing the glass of the 6146's to keep the seals cool. In AM linear service, the carrier output should not exceed HALF the total plate dissipation. A 6146 runs about 25 watts plate dissipation, so with a pair of them, you should be able to run 25 watts out. With 100% modulation in the positive direction, that would be 100 watts pep. A properly functioning AM final capable of 100% modulation should run about 33% carrier efficiency. That means that two-thirds of the input power is dissipated in the plates of the final, and one third is delivered as rf output. When the carrier is modulated, the final actually becomes more efficient, so the plate dissipation is reduced under modulated conditions. The DC input should not vary, so that simply means that some of the DC input that was being dissipated as heat is now being converted to rf output in the form of sideband power. Is that where sideband energy then is created and therefore exists as long as there's a modulate AM carrier? I wasn't in on the big discussion about this, a few months ago. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] power ratings
The plate dissipation of the 6146's is the key. Your carrier steady on should not exceed the dissipation rating. This is about 50 watts if I remember right which would give you 200 watts PEP. So your power suppl;y should be capable of about 150 watts continuous and it will handle the 200 watts on peaks. I would beef up the fan so that I had a good amount of air passing the glass of the 6146's to keep the seals cool. In AM linear service, the carrier output should not exceed HALF the total plate dissipation. A 6146 runs about 25 watts plate dissipation, so with a pair of them, you should be able to run 25 watts out. With 100% modulation in the positive direction, that would be 100 watts pep. A properly functioning AM final capable of 100% modulation should run about 33% carrier efficiency. That means that two-thirds of the input power is dissipated in the plates of the final, and one third is delivered as rf output. When the carrier is modulated, the final actually becomes more efficient, so the plate dissipation is reduced under modulated conditions. The DC input should not vary, so that simply means that some of the DC input that was being dissipated as heat is now being converted to rf output in the form of sideband power.
Re: [AMRadio] power ratings
Rev. Don Sanders wrote: Ye3s but the cost of a good modulation transformer for 300 watts or more would be as much as a SB200. Actually for a good rig you could run a pair of 813 or a high power triode similar tube at about 800 watts and cathode modulate at 400 watts. This is cost effective and works well. Tetrode tubes do not cathode modulate well. Healthfully yours, Anyone looking to buy some 450TL's? 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] power ratings
Ye3s but the cost of a good modulation transformer for 300 watts or more would be as much as a SB200. Actually for a good rig you could run a pair of 813 or a high power triode similar tube at about 800 watts and cathode modulate at 400 watts. This is cost effective and works well. Tetrode tubes do not cathode modulate well. Healthfully yours, DON W4BWS - Original Message - From: "Byron Lichtenwalner" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Monday, July 11, 2005 8:54 PM Subject: Re: [AMRadio] power ratings > Ed > Shows you what high level modulation can do, with finals running in Class C > vs. the amp running in linear mode. > Byron, W3WKR > > __ > 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] power ratings
The plate dissapation of the 6146's is the key. Your carrier steady on should not exceed the dissapation rating. This is about 50 watts if I remember right which would give you 200 watts PEP. So your power suppl;y should be capable of about 150 watts continuous and it will handle the 200 watts on peaks. I would beef up the fan so that I had a good amount of air passing the glass of the 6146's to keep the seals cool. There were several articles in old mags for the conversion of DX100 to linears for the SB10. Those would be a good start for info. Healthfully yours, DON W4BWS - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Monday, July 11, 2005 8:32 PM Subject: [AMRadio] power ratings > I want to thank everyone who responded to my question. The consensus of > opinion is that the AL-811 runs 100 watts of carrier on AM with 400 watts > PEP. This with 3X811 while my DX-100 does the same thing with 2X6146. > Doesn't sound right, does it? I have a junker HW-100 with a good PA > section. How much power could I run as a linear amp using 2X6146 and what > rating power supply would I need? 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 >
Re: [AMRadio] interference from 3810 khz to 3910 khz
I have heard that some consumer electronics that use microcontrollers operate with FM'ed clocks to reduce the Part 15 emmissions by spreading it out. And many appernetly use clocks in the 75M range. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "Geoff" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 10:12 AM Subject: Re: [AMRadio] interference from 3810 khz to 3910 khz > kenw2dtc wrote: > > > "Anyone else picking up interference from 3810 khz to 3910 khz ? It > > sounds like a swept buzzsaw" > > > > ***I work the 3870 to 3890 portion of the band and every once in a > > while, I hear it slide through the frequency like a slow VFO. Others > > on frequency from NJ to Maine also hear it. It's not on all the time??? > > > > 73, > > Ken W2DTC > > > > __ > > > I hear that in south Texas, too... > > When I hear it on some of the higher frequencies, I always thought it > might be an audio version of where the MUF was... > As screwy as the sunspot cycle has been, the MUF could have been as low > as 3.9MHz. > > > --- > 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 >
Re: [AMRadio] interference from 3810 khz to 3910 khz
kenw2dtc wrote: "Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw" ***I work the 3870 to 3890 portion of the band and every once in a while, I hear it slide through the frequency like a slow VFO. Others on frequency from NJ to Maine also hear it. It's not on all the time??? 73, Ken W2DTC __ I hear that in south Texas, too... When I hear it on some of the higher frequencies, I always thought it might be an audio version of where the MUF was... As screwy as the sunspot cycle has been, the MUF could have been as low as 3.9MHz. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] interference from 3810 khz to 3910 khz
>From the northeast I can offer the following for 75: - swisher/sweeping sound, travels up and down the band (this might be what you're hearing, Mark) - beep/buzz/duck sound, also travels the band and easily recognized by its steady short, duck-like quack/buzz sound *bzzt* *bzzt* *bzzt* *bzzt* - the sound from hell, which varies between a screeching buzz to more of a roaring sound, usually starting high-pitched and slowly going to the lower frequency roar. These sounds are heard by AMers all over the northeast, as well as elsewhere. I've probably missed a few. Some have tracked one of the sounds to (possibly) the Bath Ironworks or that vicinity, suggestions include some kind of industrial heating device. Wonder if any of it comes from Brunswick? Other odds sounds like the marching duck sound would be much harder to locate. Most seem to wander around the band after hammering one frequency for a while. Some of the more steady and strong signals located at fixed points on the band are indeed local to me. For example, my Dish satellite receiver wipes out most of 40 and up but doesn't seem to bother 75. Even the VCR and other electronics make racket while shut off. My solution was to add a terminal strip with a switch to plug it all into, that can easily be shut off for listening. Satellite receiver needs to reboot everytime, which is annoying, but it sure quiets things down. On 7/12/05, Geoff <[EMAIL PROTECTED]> wrote: > Mark Foltarz wrote: > > >Anyone else picking up interference from 3810 khz to 3910 khz ? > >It sounds like a swept buzzsaw. > >10:15 EST QTH is NE Ohio. > > > > > > > > It's interesting to note, however, that this morning on 75m, a station > 15miles away > and running 300w was S-7, while a 175w station 300 Miles away was 20db/S-9. > > typically, it's the other way around. when I signed, both of them were > unreadable > at my house, and line noise had crept up to S-8. > > Strage this morning, on 75m, from 7am to 8:30am, CST > > 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 >
Re: [AMRadio] interference from 3810 khz to 3910 khz
"Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw" ***I work the 3870 to 3890 portion of the band and every once in a while, I hear it slide through the frequency like a slow VFO. Others on frequency from NJ to Maine also hear it. It's not on all the time??? 73, Ken W2DTC
[AMRadio] FS: GP-7/ARB station, Omni VI/OPT3, AX-190, Grammar TX, HL Speaker, Signal Shifter, Bandmaster
For Sale. All prices are plus shipping. GP-7/ARB pair. Both units are reworked and mostly ready to put on the air. Both units are accessorized out the wazoo with mounts, tuning units, control boxes and all. The ARB works well (on the original dynamotor) but the wiring to the control boxes has not been done. The ARB has some rare accessories including the shock mount, the goofy ZB-3 homing adapter, and an empty spares chest. The ZB-3 is brand new with the original spares box, etc. The GP-7 has been ham modified to run on an external power supply that is only partially built. It includes the mounting rails, all the useful tuning units with steel storage boxes, etc. The GP-7 will run from any regular TX supply. I'd like $1000 for this gorgeous WWII rig. All manuals included. Ask for pictures. Ten-Tec Omni VI with a factory option 3 upgrade to make it into an Omni VI+. This has the 250 and 500 cycle CW filters in it. If there's a better receiver in a rig, I've not heard it. With power supply, desk mic and all original manuals. Working perfectly. This transceiver was originally rack-mounted and has a nasty scratch on top from whatever was mounted above it. Otherwise, looks great. $1400 Hammarlund large speaker for HQ-180 and similar. Nice shape but some scuffs along front trim. $79 Allied AX-190 ham bands receiver with matching speaker and original manual. Front panel looks great. Cabinet has some scratches, but nothing obnoxious. All original. Working well. $109 1930's Homebrew CW TX. This was built from a March, 1937 QST article by George Grammar. It is a 19" rackmount requiring 10.5" of rack space. It has a steel chassis and panel. The front panel is clean and looks like the picture in QST. I will include a copy of the construction article. This was designed to use an 804 tube in the final but this one had an 803 in the final when I found it. Uses plug in coils but these are mostly missing. It is not built exactly according to the article but it looks to be pretty close. No power supply. As-is. Needs work. From the estate of 8AIG. $40 Harvey Wells Bandmaster Deluxe HF transmitter with original VFO and original HW power supply. Also included are a set of original HW bulletins on the Bandmaster. The power supply is an open chassis design with some mild grunge on the chassis. Otherwise, this thing is really nice. Working as it sits. $300 Meissner Signal Shifter EX--rackmount version. The rack panel was a separate option and is seldom seen. Looks great. Working. $215 Thanks for looking. 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.(16b)
Re: [AMRadio] interference from 3810 khz to 3910 khz
Mark Foltarz wrote: Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw. 10:15 EST QTH is NE Ohio. It's interesting to note, however, that this morning on 75m, a station 15miles away and running 300w was S-7, while a 175w station 300 Miles away was 20db/S-9. typically, it's the other way around. when I signed, both of them were unreadable at my house, and line noise had crept up to S-8. Strage this morning, on 75m, from 7am to 8:30am, CST 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] interference from 3810 khz to 3910 khz
Jim Candela wrote: Mark, I have something similar here in Round Rock, Texas. I discovered that my DVD / VCR combo squirts out RF like crazy whenever it is turned off. Whenever I want to listen to 75 meters, I need to unplug the POS. Maybe the interference your seeing is in your own house, or maybe not. Time to put your detective hat on.. Point Of Sale? ;-)
Re: [AMRadio] FS: Heath Manuals, E-200-C, etc.
Don, I'm interested in the Megohmeter. Let me know with shipping to 78681. Jim --- Merz Donald S <[EMAIL PROTECTED]> wrote: > For Sale: Heathkit Manuals, E-200-C, etc. > > Precision E-200-C Signal Generator. Nice looking > shape in every respect. Leather handle intact. $19 > > Military AN/PSM-2 ZM-14A Megohmeter with snap-on > lid. Cool meter for 0-1000 meghohms with built-in > hand-crank generator for test voltage. $19 > > Heathkit Original Manuals. Most of these have the > oversize fold-out drawings. $6 each, 2 for $10. $1 > each for US media mailing. > > AA-1 Audio Analyzer > AG-10 Sine-Square Wave Generator > CB-1 Citizens Band Transceiver > HD-1 Harmonic Distortion Meter > IB-2A Impedance Bridge > IT-21 Tube Checker with a bunch of supplemental test > data charts > LG-1 Laboratory Type Signal Generator > PS-4 Regulated Power Supply > QM-1 Q-Meter > WA-P2 Preamplifier > > Hazeltime Electronics Corporation 500V 200ma power > supply. This is in a beat up 15x9x11 black wrinkle > steel cabinet with flip-top lid. Both volts and MA > are metered. Output is variable using a variac that > looks cooked. Filament voltage is also adjustable. > Output is taken at binding posts on front. Navy UTS > anchor symbols are stamped in several places. > Components and construction are first rate. > Rectifier tube is a 5U4 which seems over-worked in > this application to me. 2 big Thordarson chokes in > output filter. Front panel labeling must've been > done by the student intern because it is sloppy. > Minus the variac, this would need very little to be > an excellent, fixed-output transmitter power supply. > Untested. As-is. $30. Heavy-will cost more to ship > than to buy. > > Thanks for looking. > 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.(17b) > __ > 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] interference from 3810 khz to 3910 khz
Mark, I have something similar here in Round Rock, Texas. I discovered that my DVD / VCR combo squirts out RF like crazy whenever it is turned off. Whenever I want to listen to 75 meters, I need to unplug the POS. Maybe the interference your seeing is in your own house, or maybe not. Time to put your detective hat on.. Regards, Jim WD5JKO --- Mark Foltarz <[EMAIL PROTECTED]> wrote: > Anyone else picking up interference from 3810 khz to > 3910 khz ? > It sounds like a swept buzzsaw. > 10:15 EST QTH is NE Ohio. > > de KA4JVY > Mark > > > > __ > Do you Yahoo!? > Read only the mail you want - Yahoo! Mail SpamGuard. > > http://promotions.yahoo.com/new_mail > __ > 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] FS: Heath Manuals, E-200-C, etc.
For Sale: Heathkit Manuals, E-200-C, etc. Precision E-200-C Signal Generator. Nice looking shape in every respect. Leather handle intact. $19 Military AN/PSM-2 ZM-14A Megohmeter with snap-on lid. Cool meter for 0-1000 meghohms with built-in hand-crank generator for test voltage. $19 Heathkit Original Manuals. Most of these have the oversize fold-out drawings. $6 each, 2 for $10. $1 each for US media mailing. AA-1 Audio Analyzer AG-10 Sine-Square Wave Generator CB-1 Citizens Band Transceiver HD-1 Harmonic Distortion Meter IB-2A Impedance Bridge IT-21 Tube Checker with a bunch of supplemental test data charts LG-1 Laboratory Type Signal Generator PS-4 Regulated Power Supply QM-1 Q-Meter WA-P2 Preamplifier Hazeltime Electronics Corporation 500V 200ma power supply. This is in a beat up 15x9x11 black wrinkle steel cabinet with flip-top lid. Both volts and MA are metered. Output is variable using a variac that looks cooked. Filament voltage is also adjustable. Output is taken at binding posts on front. Navy UTS anchor symbols are stamped in several places. Components and construction are first rate. Rectifier tube is a 5U4 which seems over-worked in this application to me. 2 big Thordarson chokes in output filter. Front panel labeling must've been done by the student intern because it is sloppy. Minus the variac, this would need very little to be an excellent, fixed-output transmitter power supply. Untested. As-is. $30. Heavy-will cost more to ship than to buy. Thanks for looking. 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.(17b)
[AMRadio] interference from 3810 khz to 3910 khz
Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw. 10:15 EST QTH is NE Ohio. de KA4JVY Mark __ Do you Yahoo!? Read only the mail you want - Yahoo! Mail SpamGuard. http://promotions.yahoo.com/new_mail
Re: [AMRadio] power ratings
[EMAIL PROTECTED] wrote: Thanks, Gary. Ed K6UUZ On Mon, 11 Jul 2005 22:58:26 -0400 Gary Schafer <[EMAIL PROTECTED]> writes: because of the class of service. read here (http://www.qsl.net/wa5bxo/asyam/aam3.html) for a good explanation of everything related. 73 = Best Regards, -Geoff/W5OMR
