[Drakelist] Station upgrade
A most interesting thread. However may I ask for a clarification please? I have always understood, mainly from Bill Orr's wonderful but out of print books, that a 5/8 vertical had the lowest angle main lobe and hence was superior for DX to a 1/4 wave vertical, all othrer factors being equal. Is it only when longer than 5/8 that the antenna is transformed into a 'cloud warmer' or have I got it all wrong? Hope I am not being too stupid or pedantic. Damien G3XER/C6AXE___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] The Heathkit Shop L-4/L-7 Power Supply Upgrade Board
Yes, Mike does a great job ! One thing I do (it is in the directions) I test the boards, and form the caps by using a Variac. I run the voltage over a day or so up to 120 VAC...looking for 240VDC + out. Then I know when I put it in it works and feel better about the whole project. Of course..be careful as that is pretty dangerous voltage/current, but if you dont know that already...you should not work on the project in the first place! One nice thing is..when you turn off the variac...you can watch the voltage go down insuring the bleeders are working 73, Lee, KC9CDT -Original Message- From: LEE BAHR pulsa...@embarqmail.com To: drakelist Drakelist@zerobeat.net Sent: Thu, Mar 10, 2011 12:01 am Subject: [Drakelist] The Heathkit Shop L-4/L-7 Power Supply Upgrade Board I just got another batch of The Heathkit Shop L-4/L-7 Power Supply Upgrade Boards from Mike Bryce for some Drake amps around here. (Bare Boards). Everytime I look at them I am amazed at the quality of these 1/8th inch thick boards. This was my third or fourth order for them. As far as I am concerned, this is the only way to go! They truly are Upgrade Boards from original. (1/8th inch thick fiberglass, silk screened and masked for accepting modern 105 degree C snap in caps plus use of all new 3 amp diodes, 2 watt balancing resistors and 5 watt bleeder/balancing resistors and all on one board too.) I've got an old Swan Mark 1 amplifier using 3-400Z tubes sitting around here too and plan to also put one of these boards in there. (lots of room to do this). I am also thinking of installing 2 or 3 Russian GI-7BT ceramic tubes in this amp. They only cost around $20 to $25 each so they would be fun to mess plus I have some around the shack. Lee, w0vt ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] 100 KC Calib.
Byron - Yes, a more negative grid would move the tube closer to cut-off, reducing its gain. I have seen 'working' calibrators at -45 VDC though. Have you tried another tube? Anything plugged in to the ACCESSORY socket perhaps loading down the CAL signal there? What are you measuring the Pin 1 voltage with? If the calibrator is running (!) you're actually measuring the average of an AC voltage at Pins 1 and 5. The voltage chart specifies a VTVM, 11M input and assumes a 1M resistor at the tip of the probe for decoupling. Check Pin 7 to ground for DC resistance. Goes through S3 to turn CAL on and off. C118 obviously, although a pretty low failure rate. C120 also a possibility. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Byron Tatum wrote: Hello- I am going through an R-4 receiver and the 100 KC calib output is weak. The receiver sensitivity is very good. The calibrator will only push the S-meter up to 5 dB over S-9 on 80 meters, and it barely moves the meter pointer on 10 meters (S-meter at max sensitivity setting). Some of the stronger 75 meter signals are giving 40 over S-9 on this R-4. Another R-4 here moves the S-meter to around S-5 on 10 meters. I have checked voltages on the 12BA6 calib tube and all are close, except the pin #1 (grid) voltage measures -37 v. The manual says it should be around -28 V. The 1 meg grid leak measures 1.05 meg, I didn't change it out. Would the higher neg voltage on grid decrease the output? If so, should I lower the value of the grid leak? I thought I would ask before I go to trying to compare the outputs of the R-4 calibrators, or tear into the other R-4 to measure voltages, etc. Thanks, Byron WA5THJ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Station upgrade
You have it right. Up to 5/8 wavelength a vertical can be an excellent antenna. Beyond 5/8 wavelength more and more RF radiates at a high angle and the low angle lobe becomes secondary and continues to decrease in strength as the frequency goes up. So, for a 43' vertical: Length: 43.00 Frequency: Wavelength: Wavelength: Degrees: 1.825 0.085 4/47 30.7 3.550 0.166 16/9759.7 5.368 0.251 1/ 4 90.3 7.050 0.329 27/82 118.5 10.120 0.473 26/55 170.1 14.050 0.656 21/32 236.2 18.150 0.848 39/46 305.2 21.050 0.983 58/59 353.9 24.950 1.165 1 16/97 419.5 28.100 1.312 1 5/16 472.4 Since 5/8 == 0.625 you can see that on 20 meters the antenna is just a bit over 5/8 wavelength. Beyond 20 meters the antenna gets pretty long. Most of the commercial 43' antennas have a UNUN at the feedpoint (bad idea in a reactive circuit), suggest 150' of coax (the losses make the SWR measured at the rig look better) and suggest a tuner in the shack. I's suggesting that all three of those ideas are serious compromises made for the sake of convenience. Of course, in that scenario the antenna will radiate some RF, it will work. It's just that it won't work to anywhere near it's potential. And, to call the antenna an all band setup is a serious disservice to the radio community. Above 20 meters the performance will be very poor as the majority of the radiated RF will be Lost In Space. 73, -Doug, W7KF http://www.w7kf.com Damien Mannix wrote: A most interesting thread. However may I ask for a clarification please? I have always understood, mainly from Bill Orr's wonderful but out of print books, that a 5/8 vertical had the lowest angle main lobe and hence was superior for DX to a 1/4 wave vertical, all othrer factors being equal. Is it only when longer than 5/8 that the antenna is transformed into a 'cloud warmer' or have I got it all wrong? Hope I am not being too stupid or pedantic. Damien G3XER/C6AXE ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Station upgrade
This is very fine work Doug. Nice to see the reality vs. the hype. Thank you very much for the information. Best regards and '73, Mike Pappas W9CN advanceddigi...@mac.com On Mar 10, 2011, at 9:04 AM, Doug Smith [W7KF] wrote: You have it right. Up to 5/8 wavelength a vertical can be an excellent antenna. Beyond 5/8 wavelength more and more RF radiates at a high angle and the low angle lobe becomes secondary and continues to decrease in strength as the frequency goes up. So, for a 43' vertical: Length: 43.00 Frequency: Wavelength: Wavelength: Degrees: 1.825 0.085 4/47 30.7 3.550 0.166 16/9759.7 5.368 0.251 1/ 4 90.3 7.050 0.329 27/82 118.5 10.120 0.473 26/55 170.1 14.050 0.656 21/32 236.2 18.150 0.848 39/46 305.2 21.050 0.983 58/59 353.9 24.950 1.165 1 16/97 419.5 28.100 1.312 1 5/16 472.4 Since 5/8 == 0.625 you can see that on 20 meters the antenna is just a bit over 5/8 wavelength. Beyond 20 meters the antenna gets pretty long. Most of the commercial 43' antennas have a UNUN at the feedpoint (bad idea in a reactive circuit), suggest 150' of coax (the losses make the SWR measured at the rig look better) and suggest a tuner in the shack. I's suggesting that all three of those ideas are serious compromises made for the sake of convenience. Of course, in that scenario the antenna will radiate some RF, it will work. It's just that it won't work to anywhere near it's potential. And, to call the antenna an all band setup is a serious disservice to the radio community. Above 20 meters the performance will be very poor as the majority of the radiated RF will be Lost In Space. 73, -Doug, W7KF http://www.w7kf.com Damien Mannix wrote: A most interesting thread. However may I ask for a clarification please? I have always understood, mainly from Bill Orr's wonderful but out of print books, that a 5/8 vertical had the lowest angle main lobe and hence was superior for DX to a 1/4 wave vertical, all othrer factors being equal. Is it only when longer than 5/8 that the antenna is transformed into a 'cloud warmer' or have I got it all wrong? Hope I am not being too stupid or pedantic. Damien G3XER/C6AXE ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4A T4X Alignment Instruction Exceptions
Am considering alignment of an R-4A ( except for the preselector procedure ) and T-4X ( except for T4, T5, T6, T7 slug adjustment ) per the manual instructions. But, recall reading on this list that certain of the instructions should NOT be performed. Any other items other than the two I've mentioned that are to be avoided? The only problems with the R4A is audio distortion with RF gain near maximum, and the S-meter reading changing with AF gain setting. Only issue with the T-4X is 20M output is about half that for 80, 40, 15M ( haven't checked 10M ). I own the tools listed in the instructions and want to avoid shipping these rigs. 73, Curt KB5JO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A T4X Alignment Instruction Exceptions
Curt - The four slugs in either the receiver or transmitter should never be adjusted _UNLESS_ someone has already been 'fixing' them and you are SURE they are misadjusted. Receiver - I don't recommend Section VIII, C, 8 9. Again, this does not need adjustment _UNLESS_ (see above!). The adjustment is a 'little' tricky, and it's easier to mess up than improve, without 'help'. Section E, use the dimensions and frequencies in para 7. The 10M slug adjustment of the RF TUNE can be 'fudged' a little if the caps are at minimum capacity to get the alignment screws a little more tension. It's a good idea to put a dab of nail polish on the adjuster when they are this loose, otherwise your adjustment will change when you turn the receiver back over! Transmitter - Section VIII, A I just use the transmitter CO as the source rather than messing with the external generator via the INJ jack. Keep the _dipped_ plate current at 200 mA or lower to keep the adjustment peaking from being masked by the ALC. Use the dimensions and frequencies as per 16, again ensuring sufficient tension on the trimmer to hold adjustment. If you plan on using TRANSCEIVE with RCVR or XMTR control, it's best to peak the INJ trimmers on each band in both receiver and transmitter WITH the two cabled together. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Curt wrote: Am considering alignment of an R-4A ( except for the preselector procedure ) and T-4X ( except for T4, T5, T6, T7 slug adjustment ) per the manual instructions. But, recall reading on this list that certain of the instructions should NOT be performed. Any other items other than the two I've mentioned that are to be avoided? The only problems with the R4A is audio distortion with RF gain near maximum, and the S-meter reading changing with AF gain setting. Only issue with the T-4X is 20M output is about half that for 80, 40, 15M ( haven't checked 10M ). I own the tools listed in the instructions and want to avoid shipping these rigs. 73, Curt KB5JO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R-4 series freq display
Do digital freq. displays for the R-4 series actually work? Where do they plug in? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Station upgrade
I think the way to go is a SteppIR BIG IR...40-10 with resonent at all frequency's??? 73, Lee -Original Message- From: Doug Smith [W7KF] d...@w7kf.com To: drakelist drakelist@zerobeat.net Sent: Thu, Mar 10, 2011 11:08 am Subject: Re: [Drakelist] Station upgrade You have it right. Up to 5/8 wavelength a vertical can be an excellent antenna. Beyond 5/8 wavelength more and more RF radiates at a high angle and the low angle lobe becomes secondary and continues to decrease in strength as the frequency goes up. So, for a 43' vertical: Length: 43.00 Frequency: Wavelength: Wavelength: Degrees: 1.825 0.085 4/47 30.7 3.550 0.166 16/9759.7 5.368 0.251 1/ 4 90.3 7.050 0.329 27/82 118.5 10.120 0.473 26/55 170.1 14.050 0.656 21/32 236.2 18.150 0.848 39/46 305.2 21.050 0.983 58/59 353.9 24.950 1.165 1 16/97 419.5 28.100 1.312 1 5/16 472.4 Since 5/8 == 0.625 you can see that on 20 meters the antenna is just a bit over 5/8 wavelength. Beyond 20 meters the antenna gets pretty long. Most of the commercial 43' antennas have a UNUN at the feedpoint (bad idea in a reactive circuit), suggest 150' of coax (the losses make the SWR measured at the rig look better) and suggest a tuner in the shack. I's suggesting that all three of those ideas are serious compromises made for the sake of convenience. Of course, in that scenario the antenna will radiate some RF, it will work. It's just that it won't work to anywhere near it's potential. And, to call the antenna an all band setup is a serious disservice to the radio community. Above 20 meters the performance will be very poor as the majority of the radiated RF will be Lost In Space. 73, -Doug, W7KF http://www.w7kf.com Damien Mannix wrote: A most interesting thread. However may I ask for a clarification please? I have always understood, mainly from Bill Orr's wonderful but out of print books, that a 5/8 vertical had the lowest angle main lobe and hence was superior for DX to a 1/4 wave vertical, all othrer factors being equal. Is it only when longer than 5/8 that the antenna is transformed into a 'cloud warmer' or have I got it all wrong? Hope I am not being too stupid or pedantic. Damien G3XER/C6AXE ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4B No Standby or Mute
Received new Bias Filter Cap yesterday and installed it today. R4B is now working again. Thanks to help from the list again. The replacement used was a Sprauge Atom 10uf @500V which is a bit overkill but was the closest I could find from either Digi Key or AES on the day I ordered. Bias and S-Meter alignment now work perfectly. It was very interesting to note the difference in the 'magic eye' readings for the leakage tests on the old vs. new cap when testing on the old Heath C-3 meter. The eye would close down about half way on the 150V leakage test on the old filter cap and did not move at all on the new 500v cap. It sort of a tight fit and I had to ream out the holes in the p/s board a bit with my knife in order to fit the larger diameter leads on the new filter. Muting now puts the meter up to 60 over and the 40 over at 15V sets up nicely. I also received a new or newer V1 and Audio output V7 which made little if any noticeable difference but now the Rx has only 1 tube that tests a bit weak on the BK 707. Nice to have it running in the shack on a cold rainy day. Now to paint the top cover and it will be pretty decent. Nice to have it back on the air. On Thu, Feb 24, 2011 at 9:36 PM, Paul Gerhardt phgerha...@gmail.com wrote: Garey Thanks Will look some more at the electrolytics C11 or 91? (the cap between D6 and gnd) I have about 23-24V on Q4. Will keep looking Paul On Thu, Feb 24, 2011 at 6:02 PM, Garey Barrell k4...@mindspring.com wrote: Paul - OK. What you MAY be seeing is a very high ESR (dried out) C11 (I assume you mean C91 here?). Essentially this looks like a resistor to AC and lets the voltage rise to peak. -70 to -80 VDC isn't all that bad if it's really DC. You should measure about -36 VDC at the Emitter of Q4. Another possibility is a leaky C178. -45 is about right for the RF GAIN pot, R83, R123 junction. Don't forget about the MUTE shorting plug if the FUNCTION switch is anywhere past ON. This is a very high impedance circuit, and it doesn't take much to load it down. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: More troubleshooting on this one today. Pulled out the D6 diode and C11 and both checked OK on DVM and Heath Condenser checker so put parts back in and UNhooked the wire from C11 Neg side and Bias Voltage went from -45 to -135 ripple looks fine. Next I Hooked the wire back on C11 and UNhooked the white-red from the side of the RF gain pot. Now have -65 Volts at C11 (Where schematic says -80V) and S Meter is on 60 over in Standby (and all other positions). Hooked RF Gain (Red White that goes to Mode Switch) back on and C11 Voltage back to -45 V. Measured V5 voltages and all are OK except Pin 1 is -2.3 instead of -1.1. 70V and 110V and fil on the other pins are all OK. Something is pulling the bias down excessively it seems but I have run out of time and ideas for today. On Tue, Feb 22, 2011 at 11:32 AM, Paul Gerhardtphgerha...@gmail.com wrote: Got some time to poke at this some more. Voltage at V2 does not set up according to Sec 6.4.9 Bias and S-Meter Adj section of manual. 1. hook up meter 2. set -1.35 had to turn control all the way to get this voltage 3. S1 Adj sets 'ok' 4. Set -15 - very low like -3 Volts Going back to the power supply I am only getting -45V at the -80V test point, (C11 and D6) after the bias diode in the power supply. So either something is bad in the few bias supply components or something in the reading is 'dragging it down' B+ is good and both sides of power transformer ohm out the same so I think the transformer is OK. Ohming out the three diodes I get a much higher 'forward' resistance on the bias diode D6. like 15k one way and 30k the other way. The two B+ diodes have a much lower forward resistance so this may be a problem. Plan now will be to unhook the 'circuit' and see if bias goes up and if not look at D6 and C11 as R141 and R96 are both within tolerance. Any other thoughts B4 I remove the little power supply board? Paul - Same result if you unplug the MUTE cable at the receiver? FAST and/or SLOW the same? Possibly bad V1, V4 or V5, unplug one at a time. Does S-Meter go up to full scale? Voltage at TP-2? 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Paul Gerhardt wrote: My B-line has been working but today that after hooking it back up (was working on a TR-4) I noticed that the R-4b was not muting or going into Standby. In standby or ext mute (w/o short in RCA Mute)audio is distorted RF Gain only raises S Meter to 20 over or so. Something seems to have changed since I used it last a few weeks ago. Could this be a tube failing or ?? -- Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 -- Paul
Re: [Drakelist] R-4 series freq display
Neil, They can work, but I have heard many reports of issues on the higher bands. Typically they Y into the inj cable that runs between the TX/RX pair. My opinion is that the injection between the two rigs was on the edge when Drake engineered it. It is the reason that everyone always says that the TX output is low when the RX is controlling the transceiver function of the twins. 73, Ron WD8Sbb --- On Thu, 3/10/11, Neil M Califano cchange...@yahoo.com wrote: From: Neil M Califano cchange...@yahoo.com Subject: [Drakelist] R-4 series freq display To: Drakelist@zerobeat.net Date: Thursday, March 10, 2011, 1:32 PM Do digital freq. displays for the R-4 series actually work? Where do they plug in? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4B No Standby or Mute
At 04:05 PM 3/10/2011, Paul Gerhardt wrote: I also received a new or newer V1 and Audio output V7 which made little if any noticeable difference but now the Rx has only 1 tube that tests a bit weak on the BK 707. It's interesting to speculate the number of perfectly functional , but in the weak zone, tubes were/are discarded because of tube tester readings. :-) Congrats on getting the rig fixed up. I have a Bline that needs that same cap replaced in the PS. . John K5MO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] New (to me) B Line...
Hi Don! Thanks for the offer, but I would hate to use a rare NOS piece on this unit. It's not what I would call mint condition... I just was looking for one that I can see through. ;) 73! Bill V. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
