Re: [Drakelist] About to buy FS-4, but...
- Original Message - From: Neil M Califano cchange...@yahoo.com To: Drakelist@zerobeat.net Sent: Sunday, July 17, 2011 8:29 PM Subject: [Drakelist] About to buy FS-4, but... I want to take the plunge and buy an FS-4. The Drake Virtual Museum page reads, Complete general coverage, no crystals to buy. When I found the manual it seems to spec only 11.1 to 40 Mhz coverage. I suppose the manual is correct. Where is the emoticon for confused? The frequency range is the output frequency of the synthesizer, not the resultant receiving frequencies. On an R-4B the receive frequency range will be from 1.5mhz to 28.5mhz. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] About to buy FS-4, but...
Think about it Neil, that subs in the Drake crystal formula for all 500 kc ranges of frequencies from 0.0 to 29.1 megs. What more do you need?? 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R-4A PTO, Act III
Date: Sun, 17 Jul 2011 16:00:22 -0400 OK - this is starting to make a little more sense. If the ferrite is cracked or loose, this sort of thing can happen, then, right? What's the best way of extracting the slug from the coil form? Thanks for all the help... Steve, W1ES/4 From: Garey Barrell k4...@mindspring.com To: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Message-ID: 4e233f56.7010...@mindspring.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Steve - The chrome rider bar and follower should be clean, with NO lubrication. Ensure that the spring is pulling the follower FIRMLY against the bar. Examine the slug closely for any cracks or loose segments. 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 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO, Act III
Steve - This has been 'one of those' problems! Just a quick question I've forgotten if you said the PTO was stable outside the radio? IF so have you subbed the PreMixer tube? Possible load change on the PTO due to a tube anomaly? 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 Steve Wedge wrote: I may take you up on this. First, a few observations that I made tonight: 1. Voltage at the +DC supply terminal on the small board under the PTO was 9.18 V. As the frequency jumped around, this voltage did not change. I am accustomed to nominal voltages in older tube gear being not exact, so being off by 8% didn't seem to be a matter of concern. 2. Waveform on a 100 MHz scope looked good but there was a slight amount of jitter visible at 50 nS/div. 3. Interesting observation: waveform on the premixer side of L6 had some modulation on it that looked like the twists you'd see in loose rope. I'm assuming this is a little bit of cross-mod from the band oscillator. 4. Signals sound less pure (almost chirpy) when using the R-4A to control frequency. This occurs on all bands. Everything sounds great when using the T-4X to control the frequency. The T-4X has none of the problems with changing frequency when wiggling the tuning knob. The R-4A is very sensitive to all mechanical inputs. I'm also straining my eyes on this schematic and trying to figure out how the INJ works. I think it's the output from the premixer, V8, which is the difference between the PTO and the crystal band oscillator. How does the receiver know which signal (transmitter or receiver) to pick? I'm assuming there's a DC voltage on the INJ line as well as the RF signal (sorry, my eyes were crossing following the switching in the T-4X schematic). 73, Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! - Original Message - *From:* Gary Poland mailto:gpola...@cinci.rr.com *To:* Steve Wedge mailto:w1es1...@earthlink.net *Sent:* Sunday, July 17, 2011 7:06 PM *Subject:* Re: [Drakelist] R-4A PTO, Act III Steve, Except for a few PTO’s that had no output, I have not had the problems you mention with any Drakes I have owned or serviced over the years. Some that where heavily oxidized or had rusted frames I installed a piece of solder braid like the TR-7’s have. Maybe once in a while the shield would be loose and I would have to “ rework” the spring clips to make them grab better. Except for cleaning and relubing the bearings and worm shaft they just don’t seem to have problems. I have quite a few PTO parts here recovered from the Drake plant when they gave up repair service and a few complete PTO’s that had issues also from Drake. Anyway I would love the challenge if you want to send it this way and of course you would get it back. It’s too bad eBay has run the prices up so high on vintage radio gear and parts. 73, Gary ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-4C Bias Adjustment
Garey, I am not offended by any questions about whether I am doing things correctly. I need reality checks occasionally. I checked over my notes that I am keeping and see that the current did NOT dip across R45 but acted just like the RF output and peaked about midrange and fell off on both sides. I want to go back and redo some of these measurements. I removed the RF output switch on the LOAD control to make better resistance measurements on the switch. I found the contacts to be unstable out of circuit, so I am going to replace it. Maybe the connection to the LOAD shaft would hold the switch in the right position to make good contact. I don't think this is responsible for the problem, but it can't hurt to replace it. I am going to go back and recheck some of the measurements and make sure that I am tuning per the manual. Richard - Original Message - From: Garey Barrell k4...@mindspring.com Cc: drakelist Drakelist@zerobeat.net Sent: Saturday, July 16, 2011 10:23 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - I just another couple of thoughts. Looking back through the million or so messages regarding this problem, I asked if the voltage across R45 'dipped' when you rotated the PLATE control, and you replied that it did NOT, rather it peaked just like the RF output, falling off on either side. That's just not right!! :-) Please don't be offended, but you ARE tuning the PLATE control and NOT the RF TUNE control.? Just remember, 'We do this for fun ... We do this for fun ...:-) 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 Donley wrote: Garey, et al The PA tubes are Sylvania 6JB6, checked on a Hickok 600A and test good. I have seen no color to the plates of the finals. I have been doing all testing on 40 M. I came to suspect one of the sideband filters so I tried 80, 40 and 20 M., both upper and lower sideband to see what happened. I got output in excess of 125 W. to the dummy load in all cases. The cables to the wattmeter and dummy load are OK, the dummy load (switched to a Bird 8201) is OK. I took the lid off of the PA cage and placed an all purpose telescoping antenna next to the cage and ran the input into an HP spectrum analyzer. I got a very nice signal at 7.3 MHz and also very nice signals at 14, 21 and 28 MHz. There was no sign of any other oscillation of the finals. I did notice hash from the laptop computer switching power supply which went away when I unplugged it. Replacing and grounding the PA lid removed the extraneous harmonics at 14, 21 and 28 MHz. I also listened to the signal with another receiver and had a very clear sounding tone with no other noise up and down the dial. I varied the TR-4C VFO to make sure I was listening to the correct signal. I did measure the lead resistance of the Fluke leads. It is about 0.15 ohms, so the resistance of R45 will be about 2.25 ohms, closer to the nominal value. I don't think anything is wrong with the output circuitry. If there was, how could I be measuring power out to the dummy load? The wattmeter is a Swan 3000. I am not absolutely certain that it is working OK. I suppose I should try the light bulb technology that I used as a novice back when I knew it all. Now I have some reasonable equipment and don't know anything. Now, the last item puzzles me. I measured the ANT output to ground (SO-239) and it was 1.4 ohms, no way near 2.2 Megohms. RFC 7 goes to ground right at the SO-239. I would expect the DC resistance of the choke to be more than 1.4 ohms but less than 2.2 Megohms. Are we getting closer to an answer or just more confusion (I know it is the latter for me)? Awaiting further task assignments. I appreciate all the help. 73 Richard - Original Message - From: Garey Barrell k4...@mindspring.com To: drakelist Drakelist@zerobeat.net Sent: Thursday, July 14, 2011 10:27 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - OK. As others have said, we are missing something fundamental, as transmitters just do not do this!! :-) Verifying that the PA tubes ARE 6JB6 is a good idea. The Simpson is more than adequate for all but very low resistance readings, 2 - 15 ohm resistors and the voltage across them. You haven't confirmed which band you are using for test purposes. I suggest 40M. Are the PA plates showing any color that you have seen? Listen on another receiver and determine if you can hear the TR-4C on the frequency indicated by the dial reading. Once you find the signal, does it vary with PTO adjustment as expected? Since we have already measured the voltage across the three Cathode resistors and determined that they are approximately equal, nothing is gained by the risky (dangerous) measurement of 'plate' current. There is no place else for the current through R45 to come from other than the plate supply, so
[Drakelist] TR4 Latest Manual
Hi Anyone knows or have any manual (or link for donwload ) for tr4 for serial 26000 I have one for 16000 serial, but my serial have very differences in the circuit My TR4 Have some circuit near V17 (6aq5) and have one 12bz6 Tube. Thanks in advance Lw3ewz Gus Andrada ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR4 Latest Manual
Gus - What exact serial number? There are four schematics in that area, fairly close together. All eight versions are on my CD. 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 mail.speedy.com.ar wrote: Hi Anyone knows or have any manual (or link for donwload ) for tr4 for serial 26000 I have one for 16000 serial, but my serial have very differences in the circuit My TR4 Have some circuit near V17 (6aq5) and have one 12bz6 Tube. Thanks in advance Lw3ewz Gus Andrada ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO, Act III
Logging on from work: Garey, I thought about that last night and, as luck would have it, I had an extra good 6HS6, which I swapped. There was no change. The PTO seems to be a bit better with the cover removed, not the entire unit. Of course the frequency of the PTO changes considerably with the cover off. It's got me scratching my head, as there should really be no significant heat being generated in there... W1ES Date: Mon, 18 Jul 2011 10:11:15 -0400 From: Garey Barrell k4...@mindspring.com To: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Message-ID: 4e243f03.1090...@mindspring.com Content-Type: text/plain; charset=windows-1252; format=flowed Steve - This has been 'one of those' problems! Just a quick question I've forgotten if you said the PTO was stable outside the radio? IF so have you subbed the PreMixer tube? Possible load change on the PTO due to a tube anomaly? 73, Garey - K4OAH Glen Allen, VA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO, Act III
Hi Steve, The frequency of my T-4X PTO jumps upward almost exactly 100-KHz with the cover removed... I've tried several different tricks in futile efforts at trying to tame mine, including (A) unplugging the cooling fan that I added to allow everything inside to heat soak properly in the confines of my cool basement (no change), and, (B) gasketing the seam at the base of the PTO shield can with aluminum foil to better shield its contents, and to negate any effect that expansion/contraction of the shield might have upon the frequency (again, no effect). I have yet to re-enter the inner sanctum of my PTO here (far too busy with other stuff), but when I do I plan to completely swab everything down inside it that moves with isopropyl rubbing alcohol Q-tips. The frequency flutter is so very vexing for me that I'm afraid it's fast-removing the gleam in my eye that I've heretofore reserved for Drake gear---indeed, I'm almost ashamed to admit that I'm coming to more more appreciate the sheer joy pleasure of the reliability quality of signal that my old Icom 751A affords me in my portable work, as compared to the on-going grief given me thus far by the Drake Twins. That's sacrilege, I know, admitting such on a Drake Reflector, but it is, alas, a sad reality fact... ~73~ de Eddy VE3CUI - VE3XZ *** On 2011-07-18, at 12:13 PM, Steve Wedge wrote: Logging on from work: Garey, I thought about that last night and, as luck would have it, I had an extra good 6HS6, which I swapped. There was no change. The PTO seems to be a bit better with the cover removed, not the entire unit. Of course the frequency of the PTO changes considerably with the cover off. It's got me scratching my head, as there should really be no significant heat being generated in there... W1ES Date: Mon, 18 Jul 2011 10:11:15 -0400 From: Garey Barrell k4...@mindspring.com To: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Message-ID: 4e243f03.1090...@mindspring.com Content-Type: text/plain; charset=windows-1252; format=flowed Steve - This has been 'one of those' problems! Just a quick question I've forgotten if you said the PTO was stable outside the radio? IF so have you subbed the PreMixer tube? Possible load change on the PTO due to a tube anomaly? 73, Garey - K4OAH Glen Allen, VA ___ 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] R-4A PTO, Act III
Eddy, I don't think aluminum foil makes good gasketing material for two reasons. At least in this country, the shiny side of the foil is coated with Mylar which is nonconducting. In addition, aluminum oxide is an insulator as well. 73, Bob AD3K -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Eddy Swynar Sent: Monday, July 18, 2011 12:27 PM To: Steve Wedge Cc: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Hi Steve, The frequency of my T-4X PTO jumps upward almost exactly 100-KHz with the cover removed... I've tried several different tricks in futile efforts at trying to tame mine, including (A) unplugging the cooling fan that I added to allow everything inside to heat soak properly in the confines of my cool basement (no change), and, (B) gasketing the seam at the base of the PTO shield can with aluminum foil to better shield its contents, and to negate any effect that expansion/contraction of the shield might have upon the frequency (again, no effect). I have yet to re-enter the inner sanctum of my PTO here (far too busy with other stuff), but when I do I plan to completely swab everything down inside it that moves with isopropyl rubbing alcohol Q-tips. The frequency flutter is so very vexing for me that I'm afraid it's fast-removing the gleam in my eye that I've heretofore reserved for Drake gear---indeed, I'm almost ashamed to admit that I'm coming to more more appreciate the sheer joy pleasure of the reliability quality of signal that my old Icom 751A affords me in my portable work, as compared to the on-going grief given me thus far by the Drake Twins. That's sacrilege, I know, admitting such on a Drake Reflector, but it is, alas, a sad reality fact... ~73~ de Eddy VE3CUI - VE3XZ *** On 2011-07-18, at 12:13 PM, Steve Wedge wrote: Logging on from work: Garey, I thought about that last night and, as luck would have it, I had an extra good 6HS6, which I swapped. There was no change. The PTO seems to be a bit better with the cover removed, not the entire unit. Of course the frequency of the PTO changes considerably with the cover off. It's got me scratching my head, as there should really be no significant heat being generated in there... W1ES Date: Mon, 18 Jul 2011 10:11:15 -0400 From: Garey Barrell k4...@mindspring.com To: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Message-ID: 4e243f03.1090...@mindspring.com Content-Type: text/plain; charset=windows-1252; format=flowed Steve - This has been 'one of those' problems! Just a quick question I've forgotten if you said the PTO was stable outside the radio? IF so have you subbed the PreMixer tube? Possible load change on the PTO due to a tube anomaly? 73, Garey - K4OAH Glen Allen, VA ___ 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 mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO, Act III
Eddy - Sorry to hear of your dissatisfaction with Drake performance! :-) We ALL have those 'moments'.. Drake built better than 100,000 of this basic PTO over the years, so I guess it stands to reason that there might be a 'dog' or two in there... I've 'handled' several hundred of those over the last 40+ years, and haven't seen one yet that couldn't be fixed. As for the 751A, check back with me when one of those custom ICs dies. :-) 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 Eddy Swynar wrote: Hi Steve, The frequency of my T-4X PTO jumps upward almost exactly 100-KHz with the cover removed... I've tried several different tricks in futile efforts at trying to tame mine, including (A) unplugging the cooling fan that I added to allow everything inside to heat soak properly in the confines of my cool basement (no change), and, (B) gasketing the seam at the base of the PTO shield can with aluminum foil to better shield its contents, and to negate any effect that expansion/contraction of the shield might have upon the frequency (again, no effect). I have yet to re-enter the inner sanctum of my PTO here (far too busy with other stuff), but when I do I plan to completely swab everything down inside it that moves with isopropyl rubbing alcohol Q-tips. The frequency flutter is so very vexing for me that I'm afraid it's fast-removing the gleam in my eye that I've heretofore reserved for Drake gear---indeed, I'm almost ashamed to admit that I'm coming to more more appreciate the sheer joy pleasure of the reliability quality of signal that my old Icom 751A affords me in my portable work, as compared to the on-going grief given me thus far by the Drake Twins. That's sacrilege, I know, admitting such on a Drake Reflector, but it is, alas, a sad reality fact... ~73~ de Eddy VE3CUI - VE3XZ *** On 2011-07-18, at 12:13 PM, Steve Wedge wrote: Logging on from work: Garey, I thought about that last night and, as luck would have it, I had an extra good 6HS6, which I swapped. There was no change. The PTO seems to be a bit better with the cover removed, not the entire unit. Of course the frequency of the PTO changes considerably with the cover off. It's got me scratching my head, as there should really be no significant heat being generated in there... W1ES Date: Mon, 18 Jul 2011 10:11:15 -0400 From: Garey Barrellk4...@mindspring.com To: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Message-ID:4e243f03.1090...@mindspring.com Content-Type: text/plain; charset=windows-1252; format=flowed Steve - This has been 'one of those' problems! Just a quick question I've forgotten if you said the PTO was stable outside the radio? IF so have you subbed the PreMixer tube? Possible load change on the PTO due to a tube anomaly? 73, Garey - K4OAH Glen Allen, VA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] RIT retrofit for the TR-4C
Day dreaming again! I am working on the restoration of a nice TR-4C. One of the great improvements on the TR-4CW was to offer the RIT. Looking at the RIT board in the manuls makes it look like a snap to make one and add it to the TR-4C and replace the NB off/on swicth with some sort of a 10 K pot that would have a push off and off buiult into it. Any suggestions? Kris KM2KM 607 -257-1734 Team Leader Ithaca, NY ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-4C Bias Adjustment
Garey et al, I made resistance measurements on the RF Output switch on the LOAD shaft with the switch in place and wires and resistor attached. I got steady readings but wasn't satisfied. I removed the switch and made measurements just on the switch contacts. The open positions were obviously open, but the shorting functions of the switch were unstable. I replaced the switch with the only thing that I had which was a slide switch with snap-and-remain-in-position, not spring loaded for easy return. However, the LOAD shaft spring is strong enough to return the switch. EUREKA The old switch mechanism must have been locking the circuit into the RF output measurement mode. I can now adjust the bias current with the switches set in the required position. However, I can also adjust the bias current with the SIDEBAND switch set in the X position. Question 1Is this normal? I can also properly tune the transmitter. The PLATE control dips current like it should. The RF output adjusts like it should. I can tune and load the transmitter to 440 mA plate current with 185 W output on 40 M. (7.164 MHz.). I have not tried any other frequency. When I activate the mike switch I see the bias or idle current on the plate meter. Question 2Is this normal? When I huff into the mike, the plate current huffs with me. I have no operating experience with the TR-4C, so I don't know the answers to these two questions. I have a proper switch on order. A new item popped up though. When I just ever-so-slightly twist the chassis, the volume level on the speaker drops to about 20 %. I don't know what else might be affected. If I flex the chassis slightly, the volume comes back. If I press the mike switch or activate the key, which activates the relay, the volume level comes back. So it doesn't necessarily take flexure to bring it back. I am thinking bad solder joint somewhere from my continually flexing the chassis in turning it over repeatedly, or that the relay contacts are not as good as I thought they looked. I have a new relay ordered also. Anyway, the major problem seems to be fixed and I can get it on the air. Garey, I thank you very much for your help and all the others who chipped in with suggestions. The Drakelist sure works. Richard - Original Message - From: Garey Barrell k4...@mindspring.com To: Donley donley...@comcast.net Cc: drakelist Drakelist@zerobeat.net Sent: Monday, July 18, 2011 11:28 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - OK. Good idea. Sometimes it helps to just step back and look at the simple things again! :-) For 'normal' operation of the PA, with the LOAD control at minimum, adjust the PLATE control while monitoring the voltage across R45. The voltage should 'dip' at about the same place the output 'peaks'. IF you were to adjust the RF TUNE control, you _would_ see the output _AND_ R45 voltage both peak near the center and fall off on both sides. 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 Donley wrote: Garey, I am not offended by any questions about whether I am doing things correctly. I need reality checks occasionally. I checked over my notes that I am keeping and see that the current did NOT dip across R45 but acted just like the RF output and peaked about midrange and fell off on both sides. I want to go back and redo some of these measurements. I removed the RF output switch on the LOAD control to make better resistance measurements on the switch. I found the contacts to be unstable out of circuit, so I am going to replace it. Maybe the connection to the LOAD shaft would hold the switch in the right position to make good contact. I don't think this is responsible for the problem, but it can't hurt to replace it. I am going to go back and recheck some of the measurements and make sure that I am tuning per the manual. Richard - Original Message - From: Garey Barrell k4...@mindspring.com Cc: drakelist Drakelist@zerobeat.net Sent: Saturday, July 16, 2011 10:23 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - I just another couple of thoughts. Looking back through the million or so messages regarding this problem, I asked if the voltage across R45 'dipped' when you rotated the PLATE control, and you replied that it did NOT, rather it peaked just like the RF output, falling off on either side. That's just not right!! :-) Please don't be offended, but you ARE tuning the PLATE control and NOT the RF TUNE control.? Just remember, 'We do this for fun ... We do this for fun ...:-) 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 Donley wrote: Garey, et al The PA tubes are Sylvania 6JB6, checked on a Hickok 600A and test good. I have seen no color to the plates of the finals. I have been doing all testing on 40 M. I came
Re: [Drakelist] TR-4C Bias Adjustment
Richard - I _TOLD_ you it would be something simple that we missed... :-) How many times did we trace that circuit out? Yes, IDLE current can be measured in either SIDEBAND as long as the relay is closed, by keying the PTT. Start by checking the S-Meter when the audio drops. If it holds steady, then probably in the AF section. If the S-Meter drops, then the problem is probably in the IF, or elsewhere. If the S-Meter holds steady, use your screwdriver in the AF OUTPUT area, particularly the small AF Preamp board nearby, and check all the chassis screws for tightness. If they are tight, loosen a fraction and retighten. DeoxIT the headphone jack shorting contacts. If that doesn't fix it, then check surrounding chassis screws. If still there, then go through the entire radio, checking each chassis screw. If ALL are tight, then look at the leads soldered to the PC boards, especially the solid wire jumpers for cracked solder. 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 Donley wrote: Garey et al, I made resistance measurements on the RF Output switch on the LOAD shaft with the switch in place and wires and resistor attached. I got steady readings but wasn't satisfied. I removed the switch and made measurements just on the switch contacts. The open positions were obviously open, but the shorting functions of the switch were unstable. I replaced the switch with the only thing that I had which was a slide switch with snap-and-remain-in-position, not spring loaded for easy return. However, the LOAD shaft spring is strong enough to return the switch. EUREKA The old switch mechanism must have been locking the circuit into the RF output measurement mode. I can now adjust the bias current with the switches set in the required position. However, I can also adjust the bias current with the SIDEBAND switch set in the X position. Question 1Is this normal? I can also properly tune the transmitter. The PLATE control dips current like it should. The RF output adjusts like it should. I can tune and load the transmitter to 440 mA plate current with 185 W output on 40 M. (7.164 MHz.). I have not tried any other frequency. When I activate the mike switch I see the bias or idle current on the plate meter. Question 2Is this normal? When I huff into the mike, the plate current huffs with me. I have no operating experience with the TR-4C, so I don't know the answers to these two questions. I have a proper switch on order. A new item popped up though. When I just ever-so-slightly twist the chassis, the volume level on the speaker drops to about 20 %. I don't know what else might be affected. If I flex the chassis slightly, the volume comes back. If I press the mike switch or activate the key, which activates the relay, the volume level comes back. So it doesn't necessarily take flexure to bring it back. I am thinking bad solder joint somewhere from my continually flexing the chassis in turning it over repeatedly, or that the relay contacts are not as good as I thought they looked. I have a new relay ordered also. Anyway, the major problem seems to be fixed and I can get it on the air. Garey, I thank you very much for your help and all the others who chipped in with suggestions. The Drakelist sure works. Richard - Original Message - From: Garey Barrell k4...@mindspring.com To: Donley donley...@comcast.net Cc: drakelist Drakelist@zerobeat.net Sent: Monday, July 18, 2011 11:28 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - OK. Good idea. Sometimes it helps to just step back and look at the simple things again! :-) For 'normal' operation of the PA, with the LOAD control at minimum, adjust the PLATE control while monitoring the voltage across R45. The voltage should 'dip' at about the same place the output 'peaks'. IF you were to adjust the RF TUNE control, you _would_ see the output _AND_ R45 voltage both peak near the center and fall off on both sides. 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 Donley wrote: Garey, I am not offended by any questions about whether I am doing things correctly. I need reality checks occasionally. I checked over my notes that I am keeping and see that the current did NOT dip across R45 but acted just like the RF output and peaked about midrange and fell off on both sides. I want to go back and redo some of these measurements. I removed the RF output switch on the LOAD control to make better resistance measurements on the switch. I found the contacts to be unstable out of circuit, so I am going to replace it. Maybe the connection to the LOAD shaft would hold the switch in the right position to make good contact. I don't think this is responsible for the problem, but it can't hurt to replace it. I am going to go back and recheck
Re: [Drakelist] TR-4C Bias Adjustment
Richard, Congratulations and thanks for sharing! I learned a lot. I've had two TR-4C's and the both had the similar problem caused by bad relays and the bulb/socket in the RX ant. Kihwal, K9SUL From: Donley donley...@comcast.net To: k4...@mindspring.com Cc: drakelist Drakelist@zerobeat.net Sent: Monday, July 18, 2011 2:23 PM Subject: Re: [Drakelist] TR-4C Bias Adjustment Garey et al, I made resistance measurements on the RF Output switch on the LOAD shaft with the switch in place and wires and resistor attached. I got steady readings but wasn't satisfied. I removed the switch and made measurements just on the switch contacts. The open positions were obviously open, but the shorting functions of the switch were unstable. I replaced the switch with the only thing that I had which was a slide switch with snap-and-remain-in-position, not spring loaded for easy return. However, the LOAD shaft spring is strong enough to return the switch. EUREKA The old switch mechanism must have been locking the circuit into the RF output measurement mode. I can now adjust the bias current with the switches set in the required position. However, I can also adjust the bias current with the SIDEBAND switch set in the X position. Question 1 Is this normal? I can also properly tune the transmitter. The PLATE control dips current like it should. The RF output adjusts like it should. I can tune and load the transmitter to 440 mA plate current with 185 W output on 40 M. (7.164 MHz.). I have not tried any other frequency. When I activate the mike switch I see the bias or idle current on the plate meter. Question 2 Is this normal? When I huff into the mike, the plate current huffs with me. I have no operating experience with the TR-4C, so I don't know the answers to these two questions. I have a proper switch on order. A new item popped up though. When I just ever-so-slightly twist the chassis, the volume level on the speaker drops to about 20 %. I don't know what else might be affected. If I flex the chassis slightly, the volume comes back. If I press the mike switch or activate the key, which activates the relay, the volume level comes back. So it doesn't necessarily take flexure to bring it back. I am thinking bad solder joint somewhere from my continually flexing the chassis in turning it over repeatedly, or that the relay contacts are not as good as I thought they looked. I have a new relay ordered also. Anyway, the major problem seems to be fixed and I can get it on the air. Garey, I thank you very much for your help and all the others who chipped in with suggestions. The Drakelist sure works. Richard - Original Message - From: Garey Barrell k4...@mindspring.com To: Donley donley...@comcast.net Cc: drakelist Drakelist@zerobeat.net Sent: Monday, July 18, 2011 11:28 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - OK. Good idea. Sometimes it helps to just step back and look at the simple things again! :-) For 'normal' operation of the PA, with the LOAD control at minimum, adjust the PLATE control while monitoring the voltage across R45. The voltage should 'dip' at about the same place the output 'peaks'. IF you were to adjust the RF TUNE control, you _would_ see the output _AND_ R45 voltage both peak near the center and fall off on both sides. 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 Donley wrote: Garey, I am not offended by any questions about whether I am doing things correctly. I need reality checks occasionally. I checked over my notes that I am keeping and see that the current did NOT dip across R45 but acted just like the RF output and peaked about midrange and fell off on both sides. I want to go back and redo some of these measurements. I removed the RF output switch on the LOAD control to make better resistance measurements on the switch. I found the contacts to be unstable out of circuit, so I am going to replace it. Maybe the connection to the LOAD shaft would hold the switch in the right position to make good contact. I don't think this is responsible for the problem, but it can't hurt to replace it. I am going to go back and recheck some of the measurements and make sure that I am tuning per the manual. Richard - Original Message - From: Garey Barrell k4...@mindspring.com Cc: drakelist Drakelist@zerobeat.net Sent: Saturday, July 16, 2011 10:23 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - I just another couple of thoughts. Looking back through the million or so messages regarding this problem, I asked if the voltage across R45 'dipped' when you rotated the PLATE control, and you replied that it did NOT, rather it peaked just like the RF output, falling off on either side. That's just not right!! :-) Please don't be offended, but you
Re: [Drakelist] TR-4C Bias Adjustment
- Original Message - From: Donley donley...@comcast.net To: k4...@mindspring.com Cc: drakelist Drakelist@zerobeat.net Sent: Monday, July 18, 2011 12:23 PM Subject: Re: [Drakelist] TR-4C Bias Adjustment Garey et al, I made resistance measurements on the RF Output switch on the LOAD shaft with the switch in place and wires and resistor attached. I got steady readings but wasn't satisfied. I removed the switch and made measurements just on the switch contacts. The open positions were obviously open, but the shorting functions of the switch were unstable. I replaced the switch with the only thing that I had which was a slide switch with snap-and-remain-in-position, not spring loaded for easy return. However, the LOAD shaft spring is strong enough to return the switch. EUREKA Congratulations and halilulia! -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-4C Bias Adjustment
Richard - I just noticed your description of the slide switch. The original is NOT spring loaded, just a standard two position slide switch. The spring steel 'hairpin' on the LOAD shaft is all that is necessary to switch it back and forth. 73, Garey - K4OAH Glen Allen, VA - Original Message - From: Donley donley...@comcast.net Garey et al, I made resistance measurements on the RF Output switch on the LOAD shaft with the switch in place and wires and resistor attached. I got steady readings but wasn't satisfied. I removed the switch and made measurements just on the switch contacts. The open positions were obviously open, but the shorting functions of the switch were unstable. I replaced the switch with the only thing that I had which was a slide switch with snap-and-remain-in-position, not spring loaded for easy return. However, the LOAD shaft spring is strong enough to return the switch. EUREKA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] RIT retrofit for the TR-4C
Kris, Not sure how well this fit up, but there was an article in QST for adding RIT to the TR3. I had it on my TR3, but backed it out before I sold it. Jun 1966 - QST (Pg. 20) Offset Tuning and F.S.K. for the Drake TR-3 Author: Swanson, Elston H., W2PEE Although I can not speak for how to do this in a TR4cw, the concept is good. You might look at a schematic of the TR4CW/RIT and see how Drake did that. Might work for you better than the article on the TR3. Let the group now how it goes. 73, Ron WD8SBB --- On Mon, 7/18/11, Kris Merschrod k...@merschrod.net wrote: From: Kris Merschrod k...@merschrod.net Subject: [Drakelist] RIT retrofit for the TR-4C To: k4...@mindspring.com, drakelist Drakelist@zerobeat.net Date: Monday, July 18, 2011, 1:50 PM Day dreaming again! I am working on the restoration of a nice TR-4C. One of the great improvements on the TR-4CW was to offer the RIT. Looking at the RIT board in the manuls makes it look like a snap to make one and add it to the TR-4C and replace the NB off/on swicth with some sort of a 10 K pot that would have a push off and off buiult into it. Any suggestions? Kris KM2KM 607 -257-1734 Team Leader Ithaca, NY ___ 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] R-4A PTO, Act III
Steve, The T-4X puts a –30 volts on the INJ line when the XMTR position is selected. That –30 shuts down the R-4A’s premixer V8. In RCVR position the –30 volts is removed, the T-4X’s PTO output is deselected, and the R-4A’s injection is then free to be boss. 73, Gary___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] RIT retrofit for the TR-4C
Many thanks Ron and Gary, I will read that QST Mod too. I have the schematic for the TR-4Cw/RIT too (plus I have one of those so I can actually look into it phyiscially) and its simplicity got me going. But, as Gary pointed out, there seems to be some delicate work in the PTO that will need attention. This is the kind of activity I should be doing in the Winter. Too many weeds to pull outside :) 73, Kris KM2KM Kris Merschrod 607 -257-1734 Ithaca, NY - Original Message - From: Ron wd8...@yahoo.com To: k4...@mindspring.com; drakelist Drakelist@zerobeat.net; Kris Merschrod k...@merschrod.net Sent: Monday, July 18, 2011 6:01 PM Subject: Re: [Drakelist] RIT retrofit for the TR-4C Kris, Not sure how well this fit up, but there was an article in QST for adding RIT to the TR3. I had it on my TR3, but backed it out before I sold it. Jun 1966 - QST (Pg. 20) Offset Tuning and F.S.K. for the Drake TR-3 Author: Swanson, Elston H., W2PEE Although I can not speak for how to do this in a TR4cw, the concept is good. You might look at a schematic of the TR4CW/RIT and see how Drake did that. Might work for you better than the article on the TR3. Let the group now how it goes. 73, Ron WD8SBB --- On Mon, 7/18/11, Kris Merschrod k...@merschrod.net wrote: From: Kris Merschrod k...@merschrod.net Subject: [Drakelist] RIT retrofit for the TR-4C To: k4...@mindspring.com, drakelist Drakelist@zerobeat.net Date: Monday, July 18, 2011, 1:50 PM Day dreaming again! I am working on the restoration of a nice TR-4C. One of the great improvements on the TR-4CW was to offer the RIT. Looking at the RIT board in the manuls makes it look like a snap to make one and add it to the TR-4C and replace the NB off/on swicth with some sort of a 10 K pot that would have a push off and off buiult into it. Any suggestions? Kris KM2KM 607 -257-1734 Team Leader Ithaca, NY ___ 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] R-4A PTO, Act III
I thought it would be something of that nature. I have taken the PTO apart enough to slide the coil form off the slug and at least initially I don't see any cracks or loose segments. However, the diamond-shaped washer at the end of the coil came out easily as if it wasn't glued at all. It was flush with the end of the form, but I see that it could be recessed in the brown sleeve so that it is against the white coil form. Does the washer/spacer need to be flush, or bedded down against the form? I'm going to supper shortly, so won't get to look at the slug under my microscope until the table is cleared I have pics if needed. I'm going to clean the whole thing with IPA. Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. From: Gary Poland Sent: Monday, July 18, 2011 6:10 PM To: Steve Wedge Cc: drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Steve, The T-4X puts a –30 volts on the INJ line when the XMTR position is selected. That –30 shuts down the R-4A’s premixer V8. In RCVR position the –30 volts is removed, the T-4X’s PTO output is deselected, and the R-4A’s injection is then free to be boss. 73, GaryEmoticon3.gif___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-4C Bias Adjustment
An interesting follow-up question is why did the r45 viltage not dip? Curt KU8L Garey Barrell wrote: Richard - I _TOLD_ you it would be something simple that we missed... :-) How many times did we trace that circuit out? Yes, IDLE current can be measured in either SIDEBAND as long as the relay is closed, by keying the PTT. Start by checking the S-Meter when the audio drops. If it holds steady, then probably in the AF section. If the S-Meter drops, then the problem is probably in the IF, or elsewhere. If the S-Meter holds steady, use your screwdriver in the AF OUTPUT area, particularly the small AF Preamp board nearby, and check all the chassis screws for tightness. If they are tight, loosen a fraction and retighten. DeoxIT the headphone jack shorting contacts. If that doesn't fix it, then check surrounding chassis screws. If still there, then go through the entire radio, checking each chassis screw. If ALL are tight, then look at the leads soldered to the PC boards, especially the solid wire jumpers for cracked solder. 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 Donley wrote: Garey et al, I made resistance measurements on the RF Output switch on the LOAD shaft with the switch in place and wires and resistor attached. I got steady readings but wasn't satisfied. I removed the switch and made measurements just on the switch contacts. The open positions were obviously open, but the shorting functions of the switch were unstable. I replaced the switch with the only thing that I had which was a slide switch with snap-and-remain-in-position, not spring loaded for easy return. However, the LOAD shaft spring is strong enough to return the switch. EUREKA The old switch mechanism must have been locking the circuit into the RF output measurement mode. I can now adjust the bias current with the switches set in the required position. However, I can also adjust the bias current with the SIDEBAND switch set in the X position. Question 1Is this normal? I can also properly tune the transmitter. The PLATE control dips current like it should. The RF output adjusts like it should. I can tune and load the transmitter to 440 mA plate current with 185 W output on 40 M. (7.164 MHz.). I have not tried any other frequency. When I activate the mike switch I see the bias or idle current on the plate meter. Question 2Is this normal? When I huff into the mike, the plate current huffs with me. I have no operating experience with the TR-4C, so I don't know the answers to these two questions. I have a proper switch on order. A new item popped up though. When I just ever-so-slightly twist the chassis, the volume level on the speaker drops to about 20 %. I don't know what else might be affected. If I flex the chassis slightly, the volume comes back. If I press the mike switch or activate the key, which activates the relay, the volume level comes back. So it doesn't necessarily take flexure to bring it back. I am thinking bad solder joint somewhere from my continually flexing the chassis in turning it over repeatedly, or that the relay contacts are not as good as I thought they looked. I have a new relay ordered also. Anyway, the major problem seems to be fixed and I can get it on the air. Garey, I thank you very much for your help and all the others who chipped in with suggestions. The Drakelist sure works. Richard - Original Message - From: Garey Barrell k4...@mindspring.com To: Donley donley...@comcast.net Cc: drakelist Drakelist@zerobeat.net Sent: Monday, July 18, 2011 11:28 AM Subject: Re: [Drakelist] TR-4C Bias Adjustment Richard - OK. Good idea. Sometimes it helps to just step back and look at the simple things again! :-) For 'normal' operation of the PA, with the LOAD control at minimum, adjust the PLATE control while monitoring the voltage across R45. The voltage should 'dip' at about the same place the output 'peaks'. IF you were to adjust the RF TUNE control, you _would_ see the output _AND_ R45 voltage both peak near the center and fall off on both sides. 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 Donley wrote: Garey, I am not offended by any questions about whether I am doing things correctly. I need reality checks occasionally. I checked over my notes that I am keeping and see that the current did NOT dip across R45 but acted just like the RF output and peaked about midrange and fell off on both sides. I want to go back and redo some of these measurements. I removed the RF output switch on the LOAD control to make better resistance measurements on the switch. I found the contacts to be unstable out of circuit, so I am going to replace it. Maybe the connection to the LOAD shaft would hold the switch in the right position to make good
Re: [Drakelist] TR-4C Bias Adjustment
Thanks to all involved for posting all the to and fro in this thread. It's what makes reflectors so interesting and useful! 73 John K5MO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO, Act III
Hi Steve: I'm not sure it doesn't matter if the end pc is flush or not but keep it perpendicular to the core axis. You may just have found the culprit there. I like Ambroid cement but nearly anything will work as an adhesive there. A small amount of 5 min epoxy or even some carpenters glue. Curt KU8L Steve Wedge wrote: I thought it would be something of that nature. I have taken the PTO apart enough to slide the coil form off the slug and at least initially I don't see any cracks or loose segments. However, the diamond-shaped washer at the end of the coil came out easily as if it wasn't glued at all. It was flush with the end of the form, but I see that it could be recessed in the brown sleeve so that it is against the white coil form. Does the washer/spacer need to be flush, or bedded down against the form? I'm going to supper shortly, so won't get to look at the slug under my microscope until the table is cleared Winking smile emoticon I have pics if needed. I'm going to clean the whole thing with IPA. Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. *From:* Gary Poland mailto:gpola...@cinci.rr.com *Sent:* Monday, July 18, 2011 6:10 PM *To:* Steve Wedge mailto:w1es1...@earthlink.net *Cc:* drakelist@zerobeat.net mailto:drakelist@zerobeat.net *Subject:* Re: [Drakelist] R-4A PTO, Act III Steve, The T-4X puts a –30 volts on the INJ line when the XMTR position is selected. That –30 shuts down the R-4A’s premixer V8. In RCVR position the –30 volts is removed, the T-4X’s PTO output is deselected, and the R-4A’s injection is then free to be boss. 73, Gary ___ 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] R-4A PTO, Act III
Now I'll get a little too granular: should I orient it with a corner on the bottom, or let it ride on the edge of the square? Thanks, Curt, Garey and Gary for all your help so far! Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: Curt Nixon cptc...@flash.net Sent: Monday, July 18, 2011 7:11 PM To: Steve Wedge w1es1...@earthlink.net Cc: Gary Poland gpola...@cinci.rr.com; k4...@mindspring.com; drakelist@zerobeat.net Subject: Re: [Drakelist] R-4A PTO, Act III Hi Steve: I'm not sure it doesn't matter if the end pc is flush or not but keep it perpendicular to the core axis. You may just have found the culprit there. I like Ambroid cement but nearly anything will work as an adhesive there. A small amount of 5 min epoxy or even some carpenters glue. Curt KU8L Steve Wedge wrote: I thought it would be something of that nature. I have taken the PTO apart enough to slide the coil form off the slug and at least initially I don't see any cracks or loose segments. However, the diamond-shaped washer at the end of the coil came out easily as if it wasn't glued at all. It was flush with the end of the form, but I see that it could be recessed in the brown sleeve so that it is against the white coil form. Does the washer/spacer need to be flush, or bedded down against the form? I'm going to supper shortly, so won't get to look at the slug under my microscope until the table is cleared Winking smile emoticon I have pics if needed. I'm going to clean the whole thing with IPA. Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. *From:* Gary Poland mailto:gpola...@cinci.rr.com *Sent:* Monday, July 18, 2011 6:10 PM *To:* Steve Wedge mailto:w1es1...@earthlink.net *Cc:* drakelist@zerobeat.net mailto:drakelist@zerobeat.net *Subject:* Re: [Drakelist] R-4A PTO, Act III Steve, The T-4X puts a –30 volts on the INJ line when the XMTR position is selected. That –30 shuts down the R-4A’s premixer V8. In RCVR position the –30 volts is removed, the T-4X’s PTO output is deselected, and the R-4A’s injection is then free to be boss. 73, Gary ___ 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] R-4A PTO, Act III
This may be the BINGO! moment. The washer was only held in with friction, and it was riding on the flat. Off to do some gluing, I am... Thanks stay tuned! Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: Gary Poland gpola...@cinci.rr.com Sent: Monday, July 18, 2011 9:07 PM To: Steve Wedge w1es1...@earthlink.net Subject: Re: [Drakelist] R-4A PTO, Act III Steve , It needs to be oriented in a diamond shape. The brass end shaft rides in the V , not the flat. 73, Gary http://home.roadrunner.com/~w8pu ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A Passband Tuning
Carl, My passband tuning knob rotates 360 degrees on my R-4A. It was very scratchy and draggy (metal on metal) until I cleaned and relubricated it. The key was that I was told to unsolder the left side metal cover where it is tacked at the top, front and back. This gave me just enough so I could bend it out enough to clean things up in there. Its still tight, and you can't see great, but you can see enough. I used repeated applications of Q-tips and alcohol and when it still felt scratchy I put a little TV tuner lub/grease on the wobble disc. The 4 tuning slugs (visible through four 3/8 holes in the rear) should be at their maximum rearward travel when the knob is at the 9:00 position. Hope this helps. KB8BKU , Darryl in Dayton On Jul 17, 2011, at 2:46 AM, Carl Maniscalco wrote: Greetings to you all. I'm new to the Drake world and I just recently traded for a R-4A/T-4X combo that had sat unused for many years. While the equipment is in pretty decent shape over all, all of the mechanical elements were gummed up with hardened grease, oil and nicotine deposits (apparently, a previous owner was a heavy smoker). I've managed to clean them up considerably and have the PTOs on both radios working smoothly enough that I can easily tune across the band with one finger. The passband tuning on the R-4A is giving me some trouble, however. The inner shaft was frozen up completely and I was forced to remove the read panel of the PBT unit in order to clean the gunk off the shaft and tapered disk free it up. The problem is that, after reassembly, I'm not sure how how it's supposed to operate because I've never seen one in woking condition before. It seems that no matter how I adjust it, it wants to bind up a bit. So, what I'm asking is how many degrees of knob rotation should I expect? How should should the the screw and locknut on the rear panel be adjusted? Should there be friction or should the knob turn freely? Should there be any end play? Where should the thickest part of the tapered disk be when the knob is at the 12 o'clock position? Any help will be greatly appreciated. 73, Carl, KJ6BSO ___ 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] R-4A PTO, Act IV
Steve - It takes very little movement of the shield can to shift the frequency. Properly fitted, you should be able to push gently on the can without disturbing the frequency 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 Steve Wedge wrote: This Fourth Movement has no Ode to Joy. Glued in the end piece flush with the end of the coil form, oriented in a diamond. Fired up the R-4 and after warm-up, the problem came back as bad as ever. How tight does that cover have to be? The clips are a little deformed and they're fairly easy to disengage. If I touch the enclosure it is extremely sensitive. It sounds chirpy and the frequency goes up and down all the time - without touching anything. I'm about ready to up on that offer to send this out for a second set of eyes (and a second brain) to check it out. It's obvious why the asking price of this set was as low as it was when I bought it - not that I'm complaining as cosmetically these are about a 7 on the chassis and an 8 on the outside. I just want the chirping to be confined to the goldfinches outside my window :) Calling it a night... 73, Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: Gary Poland gpola...@cinci.rr.com Sent: Monday, July 18, 2011 9:07 PM To: Steve Wedge w1es1...@earthlink.net Subject: Re: [Drakelist] R-4A PTO, Act III Steve , It needs to be oriented in a diamond shape. The brass end shaft rides in the V , not the flat. 73, Gary http://home.roadrunner.com/~w8pu ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Need mic info on Shure model 19B209459P1
- Original Message - From: Jim Pruitt wa7...@charter.net To: Drakelist@zerobeat.net Sent: Monday, July 18, 2011 6:23 PM Subject: [Drakelist] Need mic info on Shure model 19B209459P1 I acquired a Shure model 19B209459P1 microphone at a hamfest a couple monts ago. It looks similar the 444 but I can not find any information on it. I think it was used on a Motorola or GE vhf base station so wonder if it is low impedance. At any rate, would anyone have any information on this microphone? Thank you. Jim Pruitt The number is probably the Motorola or GE stock number. Since you know the make and approximate model of the mic you can probably determine its impedance by some simple measurements. If its a passive mic, that is no internal amplifier, the DC resistance of the element or transformer secondary will tell you if its high or low impedance. If its active it may not matter much if the output voltage is sufficient for the transmitter you want to attach it to. If the amp has an output transformer that also should provide a clue by measuring its DC resistance. While the impedance and resistance are not the same a low impedance mic will have a resistance of a few tens of ohms and a high impedance mice several hundred to a few thousand ohms. While it may be a special of some sort it probably isn't. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
