Re: [Drakelist] MS-4 Speaker
I replaced the speaker in my MS-4 with one at the bottom of this page. It is a little expensive ($26) but it is a drop in replacement and it sounds great. The part number is: (COL) SPKR-4-57 http://www.surplussales.com/Microphones-Audio/MicroAudio-8.html 73, Bob K6GGO I need to replace the speaker in my MS-4; the voice coil failed (open). The speaker is 5 x 7 but I cannot find any for sale. Thirty years ago it would have been a no-brainer but today the replacement speaker market is dominated by car audio. Everything is multi-cone and high power. I found one speaker which advertised itself as solution for 5 x 7 or 6 x 8; it was too large to fit in the cabinet. Does anyone know of a source for these speakers? Does anyone have one they are willing to part with? Thanks, Brian NI7P ___ 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] C-Line RTTY
Alright I'm back, real life intervened for 12 or 15 hours since I asked the RTTY question. Thanks for the help guys. The first thing I thought of when I decided to do this was Garey's stories about running 4 line gear on RTTY 24/7 and it lasted for years. So I figured I had some margin for error here. My main concern was not so much wearing out the rig, it was having a sloppy signal and annoying everyone on the band. I was pretty sure I wanted to set it right before the ALC started kicking in, but I wasn't sure how to find that spot. Right before the output curve flattens out, it makes total sense now, but for some reason it eluded me. Also, I wondered about the RTTY shift circuit in the T-4XC but forgot to ask about it. Garey did a nice job of explaining that as well. In fact, I fixed another T-4XC a few years ago that had a shorted transistor in that circuit that caused the TX to always be 500HZ, or whatever, low. Garey pointed me in the right direction on that one also. I already have a fan on the back of the PA cage, (a Silenex that someone on the list recommended a while back) it works great. You would be hard pressed to feel any heat at all with your hand right on top of the finals after a long transmission (I've tried it, it's amazing). Hey, come to think of it, is installing a fan on the T-4XC considered a MOD?just kidding, don't get started again. My wife is right, I am a born troublemaker. Well, I'm through here, I have some cables to make if I am going to do this. Thanks again for the help, Bob K6GGO Bob - The C-Line does fine for RTTY. The transmitter has a jack on the back panel marked RTTY that when shorted shifts the carrier a bit to ensure that both tones (2125 - 2975 Hz 850 Hz shift,)were passed through the LSB filter unattenuated. It was originally designed when we were still using 850 shift, but is no longer of any value for today's (2125 - 2295 Hz 170 Hz shift) and should be left open. I ran multiple 4 Series transmitters on RTTY for some years, at full power and with transmissions of 30 minutes or more. You have to run them just UNDER the ALC threshold (just below where the output levels off) as you increase GAIN. PA tubes lasted a couple of years that way, with 'end of life' at 100W output max on 14.075 MHz. Obviously a small fan is a BIG help, either on top (blowing UP) or on the rear panel of the PA cage (blowing OUT). For contest type transmissions (excepting 10 minute CQs!) I wouldn't hesitate to use full power, about 340 mA. If you make long CQs, I'd back it down to about 300 mA. (~ 100W output) and the PA tubes will last 'forever'. 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 Robert Fish wrote: I have been thinking about using my C-line for the RTTY contest this weekend. How do I set the transmit audio (gain) level. Do I set it the same as SSB where the peaks are about 150ma? I am not set up here for FSK, so its going to be a sound card affair. Any general advice for C-line RTTY? Thanks, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] C-Line RTTY
I have been thinking about using my C-line for the RTTY contest this weekend. How do I set the transmit audio (gain) level. Do I set it the same as SSB where the peaks are about 150ma? I am not set up here for FSK, so its going to be a sound card affair. Any general advice for C-line RTTY? Thanks, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Sherwood Mods video
Hi Guys, I was tuning around on 15 meter CW this morning and I had my Ipad handy, so I made another video. (Oh no, not another one). This one is shorter. With all the recent discussion of the Sherwood mods I demonstrated the 600hz cw filter somewhat. The band wasn't crowded enough to demonstrate selectivity improvements, but I showed it in action anyway. I even made a DX contact in the process. Making these little videos is kinda fun. Stop me before I film again! Here is the link: http://www.youtube.com/watch?v=6R3ZVDQs4z8 73, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] problem with deoxit
Is the lesson, never trust your older brother? Bob K6GGO How I learned to be paranoid with cleaning agents: When I was a mere teen-ager, I decided to clean the mode switch in my HW-101 with some contact cleaner that my brother had brought home from work. I hosed the switch down well, waited a few minutes, and turned the rig on. The mode switch smoked. Literally. Fortunately , the HW-101 was still in production at that time, and I was able to get a new switch quickly and cheap. We don't have that luxury today. I learned an important lesson that day. 73 -Jim NU0C ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TX-4C 160 Mod ?
Hi Guys, I am not sure how good the print quality is, but the entire collection of HR magazine (or most of) has recently been made available for download in PDF or just about any format you chose here: http://www.archive.org/search.php?query=collection%3Aham-radio-magazinesort=-publicdate By the way, 73 magazine archives are also available here: http://www.archive.org/search.php?query=collection%3A73-magazinesort=-publicdate I have already spent a bunch of time searching around through this stuff. Lotsa fun. 73, Bob K6GGO I think the discussion is now about the expanded preselector dial that came with the FS4. HR magazine had home brew FS4 in Aug 1972 issue. That article had a copy of the dial in print. That might be where you can pick off a high resolution image if you have an origial. I sold my incomplete set of HR mags when I purchased the entire PDF collection. The PDF of the page that the dial is on is not that great. OTOH you might be able to use it for a starting point to do image restoration and enhancement. Aug 1972 - Ham Radio (Pg. 6) Frequency Synthesizer for the Drake R-4 Receiver Author: Stein, Robert S., W6NBI Sorry if I misunderstood the thread. 73, Ron WD8SBB --- On Tue, 12/20/11, Jim Shorneyjshor...@inebraska.com wrote: ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Transmit issues
Hi Guys, Thanks for the replies. The first thing I thought to do was re-seat the boards and I did. Well, I didn't re-seat the ones that were hidden under the display board (DR-7). I'll take it apart and re-seat them if I have to, but, I think I have isolated the problem to the pre-driver board and it doesn't plug into anything. It is bolted to a heatsink next to the PA. When it is in a failed condition, I have RF going into, but not out of, the pre-driver board. Thanks for the offer, but I already have a set of extender boards. I will find the problem eventually , I just need a schematic. I will take another look at Ron's site. Thanks again, Bob K6GGO Hi Bob: Before jumping right to looking for a flaky component, have you done the requisite re-seating of the board? Deoxit on the edge connector, and relay cleaning? FWIW Curt KU8L On 12/20/2011 3:15 PM, Robert Fish wrote: Hi Guys, I have a two part question. I noticed a few weeks ago that, on occasion, my TR-7 would not transmit when keyed. If I unkey and then key again, it would transmit. I noticed when running digital modes, which I do using VOX for keying the transmitter. Well, the last few days it has become more frequent. It also happens in cw. If I key the transmitter 10 times, maybe 3 or 4 times Ill get no RF out. I traced the problem to the pre-driver board. I always have RF in, but when it fails there is no RF going to the PA. Even though I have an early TR-7, I have the later version of the driver board. Unfortunately, I only have the schematic for the early version in my service manual. Where can I get a schematic for the later pre-driver board? Any idea what is happening here? It shouldn't be too much trouble to figure out which component is going flakey, if I can get a print for the newer board. Thanks in advance, Bob K6GGO ___ 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] TR-7 Transmit issues
I found the schematic on Ron's site. Thanks Lee. Bob K6GGO Hi Guys, Thanks for the replies. The first thing I thought to do was re-seat the boards and I did. Well, I didn't re-seat the ones that were hidden under the display board (DR-7). I'll take it apart and re-seat them if I have to, but, I think I have isolated the problem to the pre-driver board and it doesn't plug into anything. It is bolted to a heatsink next to the PA. When it is in a failed condition, I have RF going into, but not out of, the pre-driver board. Thanks for the offer, but I already have a set of extender boards. I will find the problem eventually , I just need a schematic. I will take another look at Ron's site. Thanks again, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Transmit issues
Well, it seems that the first transistor on the driver board is the culprit. Or, at least, when the transmitter fails, that is where the RF stops. It is a Motorola MPS-H20 I found the schematic on Ron's site. Thanks Lee. Bob K6GGO Hi Guys, Thanks for the replies. The first thing I thought to do was re-seat the boards and I did. Well, I didn't re-seat the ones that were hidden under the display board (DR-7). I'll take it apart and re-seat them if I have to, but, I think I have isolated the problem to the pre-driver board and it doesn't plug into anything. It is bolted to a heatsink next to the PA. When it is in a failed condition, I have RF going into, but not out of, the pre-driver board. Thanks for the offer, but I already have a set of extender boards. I will find the problem eventually , I just need a schematic. I will take another look at Ron's site. Thanks again, Bob K6GGO ___ 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] TR-7 Transmit issues
Sorry about that, I sent the e-mail before I was done typing. Does anyone have source for an MPS-H20. It looks like they aren't available. I found a reference to it on the Drake mods document. The guy says he replaces them with MRF237 because it can handle a little extra power. Apparently, he thinks the TO-92 package was border line undersized for .3 watts. Maybe that's why mine is going south (I've been running digital modes). I found these MRF237s on Ebay for 8 bucks (stick'em up). I'll pay it if I have to. Any thoughts? Bob K6GGO Well, it seems that the first transistor on the driver board is the culprit. Or, at least, when the transmitter fails, that is where the RF stops. It is a Motorola MPS-H20 I found the schematic on Ron's site. Thanks Lee. Bob K6GGO Hi Guys, Thanks for the replies. The first thing I thought to do was re-seat the boards and I did. Well, I didn't re-seat the ones that were hidden under the display board (DR-7). I'll take it apart and re-seat them if I have to, but, I think I have isolated the problem to the pre-driver board and it doesn't plug into anything. It is bolted to a heatsink next to the PA. When it is in a failed condition, I have RF going into, but not out of, the pre-driver board. Thanks for the offer, but I already have a set of extender boards. I will find the problem eventually , I just need a schematic. I will take another look at Ron's site. Thanks again, Bob K6GGO ___ 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] 5 watt levels
Hi Ron, I asked a similar question recently about SSB QRP with Drake equipment. I think some of the thread applies to CW. As usual, Garey and Jim provided good info. Here's the link: http://www.mail-archive.com/drakelist@zerobeat.net/msg17173.html 73, Bob K6GGO Hello, I wonder if anyone has tried to lower the drive to match 5 watt output level for QRP work. It think Drakes will make a excellent QRP rig. Of course I will run it at normal settings when not qrp'ing. 73 Ron, wb1hga ___ 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] New toy
Hi Guys, My wife bought me an Ipad recently. I used it to make a you tube video of my latest project and a little shack tour. It is Drake related indirectly. Here is the link: http://www.youtube.com/watch?v=_3LSM-sGxxI Don't worry this isn't spam, it's really from me. Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Sources for PTO return spring?
Hi Steve, I would probably just go to the local hardware store and pick out a spring that is a bit on the loose (less tension) side and clip a couple of turns at a time off of it until it was the proper tension. Then just bend down the last loop and hook it. I was a field service tech for Eastman Kodak years ago and we routinely lost springs while trying to get them hooked in place in some pretty tight spots down in the middle of a machine. You quickly become a spring expert if you want to keep your machines running. Bob K6GGO Going to have to try this route first. There is a spring vendor online, but at seven bucks apiece plus shipping, I'll use them as a last resort. The spring currently on this receiver looks like it would fit on a Holley 650 ;-) TNX / 73, Steve, W1ES/4 -Original Message- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Sources for PTO return spring?
I forgot to add, use an old pair of dikes for clipping turns off of a spring. It will ruin a pair of dikes in no time. (don't ask me how I know) Bob K6GGO Hi Steve, I would probably just go to the local hardware store and pick out a spring that is a bit on the loose (less tension) side and clip a couple of turns at a time off of it until it was the proper tension. Then just bend down the last loop and hook it. I was a field service tech for Eastman Kodak years ago and we routinely lost springs while trying to get them hooked in place in some pretty tight spots down in the middle of a machine. You quickly become a spring expert if you want to keep your machines running. Bob K6GGO Going to have to try this route first. There is a spring vendor online, but at seven bucks apiece plus shipping, I'll use them as a last resort. The spring currently on this receiver looks like it would fit on a Holley 650 ;-) TNX / 73, Steve, W1ES/4 -Original Message- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4X Stability: EPILOGUE (Almost!)
This has all been a most interesting exercise, nonetheless---I only hope that my ramblings herein have NOT inspired readers to unsubscribe from the list..! On the contrary, Eddy. I find this stuff fascinating. The most productive learning environments always have people who say things like, I wonder what would happen if we.? I hope you keep sharing the results of your experiments with us. 73, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] WTB T4XB 40M Crystal (18.1 MHz)
I have one, Pete. Are you good on QRZ.com? Bob K6GGO I am missing a 40M crystal for my T4XB. Any one have a spare crystal for sale. My Zip is 98368. I have a 30M Crystal (21.1 MHz) and would also consider a swap. Thanks, Pete N6QW ___ 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] Running QRP with Drake gear
Hi Guys, As some of you guys know, the ARRL sweepstakes phone contest starts in a few hours. It looks like I am going to have to some time this weekend to play radio. This is, pretty much, an exclusively US and Canada contest. I usually only compete in the CW contests if at all, but I was thinking it might be fun to see how many multipliers I can work with SSB QRP power (5 watts). The only rigs I have working well right now are a TR-7 and a C-Line. Which brings me to my question. (quicker than usual, I know). What is the proper way to run lower SSB power with a T-4XC. I know I need to keep the Plate circuit resonant no matter what power I run, but do I lower the gain control until I reach the desired power in the tune position or do I load the finals lighter (more capacitance) with the load control until I get my 5 watts. I want a clean, properly modulated 5 watt signal. (obviously). In fact, now that I think about it, how do they want you to measure it? It's not like you can just measure the carrier like CW or AM. I guess you just measure the peaks, except I don't have a power meter that does that well (WH-7). I guess I could just look at the signal on a scope and do the math. Same question for the TR-7, do I just lower the mic gain until the peaks are 5 watts? I don't think the carrier control affects SSB (at least it doesn't when I run PSK31 with the TR-7). It's not that big a deal really, It's not like I am going to win the contest. I might win my section, there was only one entry last year from San Joaquin Valley. I am curious about the right way to run low power SSB on these rigs, even though that isn't what they were designed for. Thanks in advance for your thoughts, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Running QRP with Drake gear
Jim, Garey, Thanks for the quick advice guys. I appreciate it. I think I will give the TR-7 a shot at this. If I find that I'm going too long between contacts or somebody complains about my signal, I'll just turn up the power. Like I said, this is just for fun. Unless I start really doing well, then of course I will get serious. Usually what happens is, I last a couple of hours and then I find myself in front of a football game, or throwing a ball for the dogs until their tongue hangs out (or mine does). Thanks again, Bob K6GGO Bob - First off, QRP SSB is 5W or 10W PEP. PEP is roughly equivalent to twice 'carrier' power, so you would set for 5W carrier and then modulate. A little tough to 'calibrate' without a PEP meter or a scope. But as you say, you're not too concerned about the 'letter of the law' here. The C-Line is not well suited to QRP operation on SSB. I would start out with the LOAD control at 0, which is a low as you'll get for input power, especially on the low bands. Then dip the PLATE, and if you whistle (or tone) into the mic, adjust the GAIN control for 5W output. This will give you approximately 10W PEP on SSB as seen on a scope. The WH-7 sees 5W quite easily on the low scale, certainly close enough for this purpose. The down-side of this method is that you are setting the output level by adjusting the mic GAIN, and at very low levels the S/N ratio of the AF stages degrades somewhat. The (suppressed) carrier also stays at max, so officially your carrier suppression is also degraded. It would be possible to add some capacitance on the output to allow a better match at the lower plate impedance, essentially rotating the LOAD control below 0. The BEST method would be to load the T-4XC to at least 40-50 W and hang a resistive pad on the output to reduce output to 5W! :-) Seems kinda silly though... I had some fun years ago by tuning up the T-4XB on CW, then switching to UPPER SIDEBAND (the non-X position). I worked quite a few stations including a VK6 before I bothered to measure the output. When I did, I discovered that it was right at 600 mW. :-) The TR-7 is considerably easier. I think you're correct about the CARRIER control not affecting SSB. But you should be able to go to SSB and adjust the MIC gain for 5W on a whistle or other steady tone. You should then be close to 10W PEP, and can check with a scope. Again, you're going to be in a poorer S/N ratio in the audio stages, plus most of your power is going to be in the cross-over area of the PA, reducing the 'purity of emissions' of your signal. So once more it would be best to run 40-50 W output and use a resistive pad to lower to the desired level. 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 Robert Fish wrote: Hi Guys, As some of you guys know, the ARRL sweepstakes phone contest starts in a few hours. It looks like I am going to have to some time this weekend to play radio. This is, pretty much, an exclusively US and Canada contest. I usually only compete in the CW contests if at all, but I was thinking it might be fun to see how many multipliers I can work with SSB QRP power (5 watts). The only rigs I have working well right now are a TR-7 and a C-Line. Which brings me to my question. (quicker than usual, I know). What is the proper way to run lower SSB power with a T-4XC. I know I need to keep the Plate circuit resonant no matter what power I run, but do I lower the gain control until I reach the desired power in the tune position or do I load the finals lighter (more capacitance) with the load control until I get my 5 watts. I want a clean, properly modulated 5 watt signal. (obviously). In fact, now that I think about it, how do they want you to measure it? It's not like you can just measure the carrier like CW or AM. I guess you just measure the peaks, except I don't have a power meter that does that well (WH-7). I guess I could just look at the signal on a scope and do the math. Same question for the TR-7, do I just lower the mic gain until the peaks are 5 watts? I don't think the carrier control affects SSB (at least it doesn't when I run PSK31 with the TR-7). It's not that big a deal really, It's not like I am going to win the contest. I might win my section, there was only one entry last year from San Joaquin Valley. I am curious about the right way to run low power SSB on these rigs, even though that isn't what they were designed for. Thanks in advance for your thoughts, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Deja Vu?
I was listening to 10 meters this morning on the C-Line, but the band seemed dead. (great propagation numbers but no sigs, just some guy from Texas sending CQ). So I decided to switch to 15 to look around. The calibration on 10 meters is off by 5kc or so. So I have to recalibrate the dial when I switch back to 15 meters. I turned on the calibrator and tuned in the closest cal signal (it happened to be 21075). As I tuned it in, it started changing tones as I tuned. Oh No! Now the PTO in the R-4C is doing it! I was really bummed, until I realized that this signal wasn't the calibrator. It was one of those digital modes with the slowly changing audio tones. I guess I'm a little jumpy. Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Unbalanced
Hi Guys, My wife would probably say that the word unbalanced should appear in the subject line of all my correspondence. However, in this case I am refering to a T-4XB. All this talk from Steve and the other guys about restoring their B-Line gear got me to thinking about the B-line I have on a shelf here in the shack. I acquired an R-4B and a T-4XB as part of a trade for some other equipment about a year ago. Both units have issues, but they are in pretty good shape cosmetically. The R-4B works pretty well, except 80 meters is dead. No big deal, probably a band oscillator that gave up. The T-4XB is completely inoperative. So you guys inspired me to take the T-4XB off the shelf and get started on it. After firing it up, I poked around with a scope and found the PTO and all the pre mixer signals were present and looking fairly reasonable. But there was nothing for them to mix with as the carrier oscillator was dead. I did some resistance checks around V1 and found only 22 ohms of resistance between the cathode and grid. It should be around the value of R1 (220K) A visual inspection revealed some corrosion on and around C2 (chassis mounted trimmer) I shot some de-oxite in there and worked it back and forth a litttle. The DC resistance was now closer to what I expected to see. So I turned it on and put it in tunevoila... I have some plate current. I found C2 was not salvageable because it was acting like two fixed capacitances when I tried to adjust the carrier oscillator. All the signal would be going through one sideband then as I adjusted C2, the signal would jump to the other sideband (no in between). I have a T-4XB carcass without many parts on it, but as luck would have it C-2 was one of the parts still there. I installed it and was able to put the carrier oscillator on frequency. Next I tuned it up and it behaved pretty well except low power out (about 80 watts on 40m). I wasn't alarmed as I haven't attempted an alignment yet and who knows what shape the finals are in. But at least now I can call it a transmitter instead of a paper weight. Next I decided to try an alignment. Any further issues should reveal themselves during an alignment. It didn't take long. I first tried to adjust the carrier balance. I had a heck of a time finding the right combination of C6 and R4. I put a scope on the output and finally got it close but R4 is all the way clockwise and the carrier wasn't completely nulled. I was thinking maybe I was on the outside slope of the M if you know what I mean. But I cant find another null more in the middle of R4's range. Then, for some reason, I remembered reading somewhere that Garey (I think it was Garey) tests transmitters sometimes by playing music from a CD through a transmitter and listening to it on another receiver in the shack. I thought this might be a way to figure out how close I am in this adjustment (plus it would be fun). So, after configuring a hideous combination of plugs, cables and adapters, I hooked my computer audio out to the microphone input on the T-4XB. At this point I should say that if you heard Al Green or Frank Sinatra (I know, I'm weird) on 40 meters last night it wasn't your imagination. I forgot to switch the antenna to dummy load for the first minute or so. My wife stopped by the shack to say good nite last night and I said, Look, I'm picking up Frank Sinatra on my ham radio receiver. She said,That's nice dear, Goodnight and off to bed she went. It is hard to impress that woman. The bottom line is, audio sounds great on USB, but a little tinny on LSB and the carrier balance pot is all the way clockwise. I checked the value of the resistors in the Carrier balance pot circuit and they seemed ok but I checked them in circuit, so who knows. Any ideas on the likely cause of this is? Balanced modulator diodes? C6? I could haul everything out and check it one at a time but that would take forever. Sorry for the long winded post but I enjoy reading other folks adventures, so why not contribute? I remain, as always, unbalanced. Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC PTO chirps
Hi Guys, I have good news to report. I have the PTO back in the T-4XC and it is working fine. It turned out to be the hardened grease in the PTO ball bearings causing the chirp and warbling after all. It didn't seem to be a plausible cause to me for the symptoms I was experiencing. But before I started changing parts out, I decided to clean the ball bearings and the drive screw and it did the trick. AS for the PTO not working after I reinstalled it into the transmitter, it turned out to be an intermitant connection on the center tap of the PTO coil. Gary told me to check it. Visually it looked OK, but when I pressed on the connection, the oscillator came alive on the scope screen. Gary is amazing he can repair radios from thousands of miles away. So I cleaned up the connection and reflowed it. It is back in the T-4XC and working great now. In fact, right after I got everything back together I heard ZK2V on 10 meters running split. A perfect opportunity to test the Transmitter PTO. He was calling for just EU for a while, but when he asked for USA I started calling 3kc up. I got him on the 3rd or 4th call. That's a new one for me. Niue, I think it is an island down in the south Pacific somewhere. Not very difficult for me on the west coast but, stil a good test for the PTO. This was only 15 or 20 minutes ago, he is still there on 28011 if your interested. Anyway that's the end of this adventure. You guys will hear from me again next time I break something. 73, Bob K6GGO Hi Guys, Here is an update on my T-4XC PTO adventure. I eventually removed the PTO from the transmitter and put it in a panavise on my bench, powered it up and listened to it on my TR-7 with a sniffer wire. While monitoring the tone, I tapped on the rod that carries the ferrite slug. It would make the frequency change and stay on the new frequency every time I tapped it. As an experiment, I opened up the R-4C and tapped on the end of the slug shaft on it. On the R-4C, the frequency would change but always return to the original freq. To make a long story short, I found hardened grease in the ball bearing races. I cleaned the ball bearings, races and the drive screw with denatured alcohol. The frequency returns to the same tone now every time I tap it and the warbling is gone when I turn the knob. I was and am convinced I fixed the problem. Here is the part where Murphy rears his ugly head. I put the PTO back together and reinstalled it in the T-4XC and presto!!what? dead silence. I used the PTO to control the R-4C still dead silence. I checked power and ground it looks fine but still, nary an oscillation from the PTO. So I unsoldered the wires and hauled it's sorry a?!%#$ back onto the bench. Powered it up and still nothing. Obviously, I hosed it somehow during the re-install. I looked for a solder problem around the output terminal it looked ok, but there were a couple of strands of wire from the old connection that the solder sucker (me) missed, but they weren't touching anything. Maybe they were touching something when it was installed, I don't know. At any rate, its dead now and I suspect a semiconductor. here are my questions: (about time eh?) I have the diodes in stock but not the FET or the buffer transistor. If I have to make a Digikey (or Mouser) order anyway, maybe I should just shot gun the thing and put in all new parts except the coils. I also have a PTO from a parts rig that has issues. I would like to rebuild it as well. Will I get into problems with tolerance stackups? I suspect that is why there are select at test caps in there. Can I replace the coax that goes from the PTO output to the wafer switch with RG-174? (to give myself a small service loop, to make the re-install easier) If it turns out to be a cap, or if I shotgun it, is there a modern replacement for those horseshoe caps? Is there anything special about the temperature compensating caps, like a backwards temp coefficient for bucking freq drift or something? Is there an easy replacement for those? Sorry for the long post about my epic struggle against the evil Murphy. If the 49ers hadn't won, it truly would have been a lost weekend. Thanks as always, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC PTO chirps
I meant Dogbone caps, not horseshoe. Sheesh. Hi Guys, Here is an update on my T-4XC PTO adventure. I eventually removed the PTO from the transmitter and put it in a panavise on my bench, powered it up and listened to it on my TR-7 with a sniffer wire. While monitoring the tone, I tapped on the rod that carries the ferrite slug. It would make the frequency change and stay on the new frequency every time I tapped it. As an experiment, I opened up the R-4C and tapped on the end of the slug shaft on it. On the R-4C, the frequency would change but always return to the original freq. To make a long story short, I found hardened grease in the ball bearing races. I cleaned the ball bearings, races and the drive screw with denatured alcohol. The frequency returns to the same tone now every time I tap it and the warbling is gone when I turn the knob. I was and am convinced I fixed the problem. Here is the part where Murphy rears his ugly head. I put the PTO back together and reinstalled it in the T-4XC and presto!!what? dead silence. I used the PTO to control the R-4C still dead silence. I checked power and ground it looks fine but still, nary an oscillation from the PTO. So I unsoldered the wires and hauled it's sorry a?!%#$ back onto the bench. Powered it up and still nothing. Obviously, I hosed it somehow during the re-install. I looked for a solder problem around the output terminal it looked ok, but there were a couple of strands of wire from the old connection that the solder sucker (me) missed, but they weren't touching anything. Maybe they were touching something when it was installed, I don't know. At any rate, its dead now and I suspect a semiconductor. here are my questions: (about time eh?) I have the diodes in stock but not the FET or the buffer transistor. If I have to make a Digikey (or Mouser) order anyway, maybe I should just shot gun the thing and put in all new parts except the coils. I also have a PTO from a parts rig that has issues. I would like to rebuild it as well. Will I get into problems with tolerance stackups? I suspect that is why there are select at test caps in there. Can I replace the coax that goes from the PTO output to the wafer switch with RG-174? (to give myself a small service loop, to make the re-install easier) If it turns out to be a cap, or if I shotgun it, is there a modern replacement for those horseshoe caps? Is there anything special about the temperature compensating caps, like a backwards temp coefficient for bucking freq drift or something? Is there an easy replacement for those? Sorry for the long post about my epic struggle against the evil Murphy. If the 49ers hadn't won, it truly would have been a lost weekend. Thanks as always, Bob K6GGO Garey, Eddy, Paul, Curt and Steve, Thanks for the quick replies guys. This is a great bunch on this list. I am convinced that it is the PTO. If I lightly tap on the PTO can with a pencil tip (and I mean very lightly) it causes the signal to jump around. Maybe just a cold solder joint. I have a parts radio (T-4XC) with a PTO in it. I guess I'll haul it out and test it. If it's stable, I will swap it with the faulty one. Can I then rebuild (shotgun) the bad PTO with all new parts? or is there special parts in there that I have to be careful with? I probably have most of the stuff in stock (NPO caps, metal film resistors etc.). It would be handy to have a nice new spare because I also have a B-Line. Also, A 5Mhz PTO is a nice thing to have around, homebrew QRP rigs etc. I have a HP signal generator, so I think I will try Paul's suggestion on the Lissajous display. Perhaps I can find the faulty component with some freeze spray and make this a quick repair. Maybe learn something in the process (heaven forbid). I wrote this e-mail in three sittings as real life keeps intervening. The bottom line is, thanks for all the help, I will let you know how I proceed and the results thereof. 73, Bob K6GGO On 2011-10-26, at 1:16 PM, Steve Wedge wrote: Removing the PTO - at least with the A's and B's - requires removal of the front panel. This is a good time to clean it as well as the fiducial window. Use only dish soap for the window or you'll take off the red line! */ /* */Hi Guys,/* Well, I can not vouch for the A B series, but in my T-4X transmitter /that/extensive a dis-aasembly is most assuredly */NOT/*required... After removing the three tubes immediately behind the PTO can, the can itself is extricated by first dis-connecting the top grounding spring, then lightly squeezing together the side prongs that hold the can in place, one prong at a time (this is by far the /WORSE/part of the operation, and the most time-consuming). The can is slipped off the assembly, rearward (where the 3 tubes were). Next, with a pair of long needle-nose pliers, each brass spacer that you see at the front of the vertical PTO board is
[Drakelist] T-4XC Unstable PTO (I think)
Hi Guys, I have been ignoring an issue with my T-4XC until recently. When I use the R-4C PTO to control the receiver it seems to work fine. When I use the T-4XC PTO to control the receiver I get sort of a chirpy, jumping around of the cw signal I am trying to copy. Both units work fine in transceive using the R-4C PTO, which is the way I have been using them. But with the recent DX expeditions (T32C, TX7M) running split, I have been having to use the C-line as separates to work them. I have had some success working them, but heaven knows what my signal sounds like. I have been putting off fixing this problem as I felt it was probably the PTO and I haven't been in the mood for performing major surgery lately. I decided to get off my arse and do something about it yesterday. So, I got out the scope and took a look at the T-4XC PTO output while it was controlling the R-4C. It seems stable. So I looked at the Plate of V-8 with the scope, I have a composite signal (PTO, Xtal Osc.) it looks solid as a rock. So then I looked at the injection signal right at the jack on the back of the T-4XC and once again, I can hear a cw signal I tuned in on the R-4C jumping all over the place, while I'm looking at a rock solid injection sig leaving the T-4XC. I switch back to the R-4C PTO and the jumping around stops, the receiver copies the same cw sig with stability. What am I missing here? It is hard to fix something when it seems like the only evidence of a problem is coming out of the speaker. If I could find some evidence of the problem I could follow it to it's source. This could be operator error (probably is) I only put about an hour in to this last night as I got called to dinner and a man has to have priorities. I am going to dig in to it this morning, I will eventually find the problem, but maybe you guys can save me some time. Ohanother clue: When I use the spot function, in CW mode, I get a warbling sound in the R-4C instead of a solid cw tone when tuning in the T-4XC sig with the receiver. It seems sort of intermittant (it switches to a cw tone sometimes and then goes back to warbling like you get in SSB mode with the spot function.) Thanks in advance, I hope this long winded post made sense. Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Unstable PTO (I think)
I know Eddy, I was going to mention your recent adventures in my opening post. Does it sound like the same issue your PTO had? yours was in a R-4 or R-4A as I recall, not that it matters. There was something about a dogbone cap in the PTO. Maybe I should go back and read that thread, eh? Bob K6GGO */Hi Bob,/* Don't even /START/me on this topic!!! * : )* */~73~ de Eddy VE3CUI - VE3XZ/* * On 2011-10-26, at 10:32 AM, Robert Fish wrote: Hi Guys, I have been ignoring an issue with my T-4XC until recently. When I use the R-4C PTO to control the receiver it seems to work fine. When I use the T-4XC PTO to control the receiver I get sort of a chirpy, jumping around of the cw signal I am trying to copy. Both units work fine in transceive using the R-4C PTO, which is the way I have been using them. But with the recent DX expeditions (T32C, TX7M) running split, I have been having to use the C-line as separates to work them. I have had some success working them, but heaven knows what my signal sounds like. I have been putting off fixing this problem as I felt it was probably the PTO and I haven't been in the mood for performing major surgery lately. I decided to get off my arse and do something about it yesterday. So, I got out the scope and took a look at the T-4XC PTO output while it was controlling the R-4C. It seems stable. So I looked at the Plate of V-8 with the scope, I have a composite signal (PTO, Xtal Osc.) it looks solid as a rock. So then I looked at the injection signal right at the jack on the back of the T-4XC and once again, I can hear a cw signal I tuned in on the R-4C jumping all over the place, while I'm looking at a rock solid injection sig leaving the T-4XC. I switch back to the R-4C PTO and the jumping around stops, the receiver copies the same cw sig with stability. What am I missing here? It is hard to fix something when it seems like the only evidence of a problem is coming out of the speaker. If I could find some evidence of the problem I could follow it to it's source. This could be operator error (probably is) I only put about an hour in to this last night as I got called to dinner and a man has to have priorities. I am going to dig in to it this morning, I will eventually find the problem, but maybe you guys can save me some time. Ohanother clue: When I use the spot function, in CW mode, I get a warbling sound in the R-4C instead of a solid cw tone when tuning in the T-4XC sig with the receiver. It seems sort of intermittant (it switches to a cw tone sometimes and then goes back to warbling like you get in SSB mode with the spot function.) Thanks in advance, I hope this long winded post made sense. Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net mailto: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] T-4XC PTO chirps
Garey, Eddy, Paul, Curt and Steve, Thanks for the quick replies guys. This is a great bunch on this list. I am convinced that it is the PTO. If I lightly tap on the PTO can with a pencil tip (and I mean very lightly) it causes the signal to jump around. Maybe just a cold solder joint. I have a parts radio (T-4XC) with a PTO in it. I guess I'll haul it out and test it. If it's stable, I will swap it with the faulty one. Can I then rebuild (shotgun) the bad PTO with all new parts? or is there special parts in there that I have to be careful with? I probably have most of the stuff in stock (NPO caps, metal film resistors etc.). It would be handy to have a nice new spare because I also have a B-Line. Also, A 5Mhz PTO is a nice thing to have around, homebrew QRP rigs etc. I have a HP signal generator, so I think I will try Paul's suggestion on the Lissajous display. Perhaps I can find the faulty component with some freeze spray and make this a quick repair. Maybe learn something in the process (heaven forbid). I wrote this e-mail in three sittings as real life keeps intervening. The bottom line is, thanks for all the help, I will let you know how I proceed and the results thereof. 73, Bob K6GGO On 2011-10-26, at 1:16 PM, Steve Wedge wrote: Removing the PTO - at least with the A's and B's - requires removal of the front panel. This is a good time to clean it as well as the fiducial window. Use only dish soap for the window or you'll take off the red line! */ /* */Hi Guys,/* Well, I can not vouch for the A B series, but in my T-4X transmitter /that/extensive a dis-aasembly is most assuredly */NOT/*required... After removing the three tubes immediately behind the PTO can, the can itself is extricated by first dis-connecting the top grounding spring, then lightly squeezing together the side prongs that hold the can in place, one prong at a time (this is by far the /WORSE/part of the operation, and the most time-consuming). The can is slipped off the assembly, rearward (where the 3 tubes were). Next, with a pair of long needle-nose pliers, each brass spacer that you see at the front of the vertical PTO board is grasped (so the spacers won't fall get lost), and a slotted screw driver is used to unscrew the 4 screws that go through them. The PTO board coil assembly is now loose, save for the 3 wires that are attached to the front vertical board: draw a simple sketch showing where these are connected so that you'll remember when you re-assemble everything, then touch each point on the board with a soldering iron to release each wire... The entire assembly is then slipped back off of the brass rod with the ferrite slugs on it. Absolutely /no need/to remove the front panel, no need for /anything/that complicated, or involved... To re-assemble, simply reverse this procedure! Hi Hi */~73~ de Eddy VE3CUI - VE3XZ/* ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T4XB Question
Hi Pete, This guy has a multi-section cap available for the T-4XB. It looks like it may be the correct cap (similar values). I have not done business with him, but I have heard good things about him. http://www.hayseedhamfest.com/capinfoT4X.htm Good Luck 73, Bob I am in the process of refurbishing a T4XB that has been significantly modified. (This is more like a detective story and whodunit or done what?) The can electrolytic which I believe is a combination of C129 and C140 was removed from the T4XB and a metal plug was fitted to the chassis. I have a manual I downloaded and in the spare parts list is the following entry for a combination electrolytic C129 = 20 Mfd @ 250 Volts C140 = 10 Mfd @ 25 Volts The schematic from the same downloaded manual shows C129 as being 60 MFd. In this T4XB, C129 has been replaced with a 60 MFd @ 350 Volt radial electrolytic that was cable tied underneath the chassis to hold it in place. Thus two questions: 1) Which is the correct value? (I would think having the larger value of capacitance is more desirable especially since this is in the plate circuit of the 12AX7.) 2) I have no problem with having something different in the radio so long as it is electrically correct. But is there any chance the dual electrolytic originally installed is available from some source. The can as originally installed appears to have no insulating ring and the three ears on the can were simply bent over and soldered to the chassis. Or is on the unobtainium list? Thanks in advance. Pete N6QW ___ 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] Drale Fuse
I've never tried this, but couldn't you just clip the leads off of a cap or resistor from your junk box and solder them on to the end caps of a regular 8a fuse. You would certainly reflow the inside connection but as long as you still have continuity when your done, no harm no foul. I wouldn't do this on spacecraft or life support equipment, but the filaments of a T4XB I think would be OK. If it fails later, it fails open, so I don't see any risk. Just make sure you use leads that can handle 8amps. (there probably is a reason for not doing this, but I can't think of it). Bob K6GGO Greetings, Trying to find a source for the 8 Amp fuse with pig tails that solders into the filament string on the T4XB. Can find the fuse but not with pig tails, any help would be appreciated. Thanks. 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
[Drakelist] FS-4 Replacement?
Hi Guys, I have an IQPro VFO that I built for a Direct conversion receiver I am building. It is a 9854 based DDS VFO designed by Craig AA0ZZ. I have decided to go a different route with the DC receiver LO. That leaves me with a perfectly good VFO to find a use for. I thought that maybe it would work as a crystal eliminator to give me general coverage for my R-4C (and R-4B). What do you guys think, will this work? What levels and impedance do those receivers look for at the accessory crystal sockets? I don't mind a few birdies as long as I know where they are and there aren't thousands of them. My first thought was; This is probably more difficult than it seems or I would have heard about more people doing it. Thanks as always, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4X alignment anomalies
Hi Gary and all, I have the B-line and C-line cd's. I don't see a troubleshooting sheet in there on either one. Does one exist for the C-line and b-line transmitters. I have often wondered what levels I should be seeing at the various stages of my T-4XB and T-4XC. Do the p-p levels you mention here hold true for the later models. The TR-7 manual has levels all over the place, not so lucky with these guys. 73, Bob K6GGO Steve - A weak PreMixer tube may be the culprit. Of course low BAND or PTO output are also possible causes. There is a troubleshooting sheet for the T-4X in the MISC files of the CD, including expected levels. Essentially, 4V p-p for the BAND, 2V p-p for the PTO, and 6V p-p for the PreMixer. ___ 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] Anyone ever look inside the PBT box?
'RTFCD!!' This actually made me laugh before I had my coffee this morning, very unusual indeed. Definitely words to live by. Bob K6GGO Steve - Um, if you would bother to look at your B-Line CD, in the MISC directory, there is a file called 'PB Tuner Mechanical'. Hidden in there is a procedure for opening, cleaning and closing the PB Tuner!! The problem is the same as the PTO, the original grease has hardened and is not allowing the slug carriage to move smoothly. As some have said, 'RTFCD!!' :-) 73, Garey - K4OAH Glen Allen, VA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Copper chassis restoration
Hi Steve, I have had some limited success with Naval jelly. It seems to stop and remove the rust pretty well. Like you said, it isn't going to look like new. Whatever damage the rust did will still be there (pitting, bare steel etc.). But, it is much cleaner looking after it is cleaned up. When I'm done, I just hit it with a coat of lacquer to keep air from getting to it again and starting the process all over. It does leave shiny copper where you use it, so it won't match the rest of the old copper. The only thing that will fix that is time. It isn't a perfect solution, but it is much better than rust and corrosion left unchecked. Bob K6GGO I am usually amazed at how well the copper chassis clean up with simple aids like 409 and Charlie's Soap (wonderful stuff only available in my area of NC). I've seen the Flitz-and-Dremel (or should that be Flitz-und-Dremel ;-) ) technique on WB4HFN's website and am still a little disappointed in how a larger area of corrosion will look after this process. I've seen some hobbyist paints, as well as Krylon, offered in a copper color. Has anyone tried any of these? I'm just looking for something that will mask the ugliness somewhat and realize it will never perfectly match. There's an area about 1 x 2 near the PTO of my new R-4B that has all the hallmarks of Pepsi Syndrome and I'd like to both protect and dress-up the area a little. Again, not going to make it a museum piece - just looking for ways of doing the equivalent of bondo to take the ugly away... 73, Steve ___ 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] thoughts
Hi Ron, I remember reading a tip once on one of these lists about tuning your transmitter by putting it in spot mode and finding the signal with your receiver and peaking the pre-selector and the plate using the receiver's s-meter. Well, it worked ok for me on the pre-selector, but I could never get a peak with the plate control (the most important one for your finals). But, through eperimentation I stumbled across a way that works great for me. I put the transmitter in tune with the gain turned all the way down. Then find the signal with the receiver. The signal should still be very strong. Then I just peak everything for the highest s-meter reading. If the s-meter is too high, tune the receiver slightly off frequency to get a lower s-meter reading so you can easily see the peaks. once you have peaked everything, it should be very close to resonance and you can then turn the gain up and touch up the tuning again. This way your finals aren't being driven very hard or at all when your searching around for the correct plate adjustment. It works for me because I was also nervous and way too slow using the conventional method of tuning up. Have Fun, Bob K6GGO I have been using a homebrew tuning 'pecker' for years without ruining the finals in my Drake's or my SB200 amp. They allow tuning the finals without stressing them. The only requirement is that you use a peak reading wattmeter. Here is a link if you are interested. http://www.3898pecker.com/ 73' Jerry K4FJK -Original Message- From: ron Sent: Friday, August 05, 2011 11:20 AM To: drakelist@zerobeat.net Subject: [Drakelist] thoughts Gang, I been enjoying the Drake TR4C for a spell, then let it rest awhile while using my current solid state radios. I decided to return to Drakes and whoa! I forget how to tune these babies. I had to re-learn (has something to do with my grey hair I suppose). I was wondering if you guys get nervous too during the tuning process so as not to ruin the finals. It just scares me sometimes 72 Ron, wb1hga ___ 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
[Drakelist] Looking for Clean B-Line
Hi Guys, I am looking to buy a clean Drake B-line, or a clean R-4B and I will add the T-4XB later. I might be willing to trade a nearly new Flex 3000 for a nice B-line and some dollars. Otherwise, I would just like to buy a clean B-line or the pieces thereof outright for cash. Thanks for the bandwidth, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] AC-4R kit
I've built two AC-4R's with Mike's kits and they worked fine right away. I got stuck a couple of times, but with a quick check of the schematic and an application of a bit of common sense I got through it. It really wasn't that difficult to figure out. He provides a great product and I haven't made my last purchase from him. By the way, which end of the soldering iron does get hot? OUCH! Never mind. Bob K6GGO Boys and girls... Well since I'm getting beat up here, I may as well defend my honor. ___ 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] AM Filters for the R4C
Hi Kevin, I have an R-4C and a TR-7. The R-4C just has a resistor in the AM slot. Whereas the TR-7 has an actual 6KHZ filter in it's AM slot. I have to admit the AM does sound better with the filter (less noise, all signal). There is a company named INRAD (nice folks) that will sell you a 6KHZ AM filter for your R-4C. Here is a link right to the page of the filter: http://www.inrad.net/product.php?productid=182cat=100page=1 Unfortunately, they are $130.00. You can keep an eye on Ebay for one, but even there they are going to set you back 75 or 100 bucks. I keep hoping one is going to fall out of the sky and hit me on the head (or land in my backyard) but it hasn't happened yet. Good Luck 73, Bob K6GGO Hi All, I am thinking I might like to narrow the AM bandwidth just a little in my R4C. I am thinking of a 6 kHz filter. Can any of you tell me what is available out there in that bandwidth and what you think the approximate cost might be? Thanks much and very 73. Kevin :) Amateur Radio: K7RX ___ 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] Slug Tuning Club
Hi Curt, I was thinking of buying one of those at one time. While collecting info, I found that one of the R390A gurus had made a couple of videos about the dissassembly, care and feeding of the beasts. These were like 8 or 12 hours of video so probably very detailed. They are for sale somewhere on the net. Not cheap either, around a 100 bucks, but seems worth it, if you own one and want to service it. Sorry, I don't remember where or who. I'll look around and see if it is in my notes. Have Fun 73, Bob K6GGO Good Morning All: I know this is slightly off topic but that great minds think alike. Over the weekend, I took the opportunity to acquire a R390A..ser 3981 Collins tagged, 1955. It appears to be unaltered, complete, even to the original military power cord. Appears to have never had any modules changed. Anyway, I have found loads of info online including the y2k manual. I suspect there are others on this list that seriously work with these amazing radios ..are there any reflectors or forums you would recommend similar to this one but for the R390A? Thanks Curt KU8L ___ 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] Low power out on 15 meters ( 10 meters too)
Hi Guys, I was up checking out activity on 17 meters today. There wasn't much. Surprise surprise, but it reminded me of a problem my T-4XC has. I have been ignoring this issue for a while now because the bands have been so dead. I tuned up the transmitter so I could call CQ on 17 meters today and I barely got 60 watts out. On 10 meters, it's more like 50 watts. It is any band that uses those two band switch positions 21.0 and 28.5 MHZ. I get over 100 watts on all the other bands, quite a bit more than a hundred on 80 meters. I suppose I could tune her up on 40 meters and then write down some power levels at various places along the transmit chain and then go back and do it on 10 or 15 meters and narrow it down to a section that way. I would expect the higher bands to be somewhat lower power, but not that much, or am I wrong. Is there anyplace I should start looking. Thanks 73, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Carrier Oscillator Issues
Hi Guys, I have a T-4XC that I thought I repaired. I replaced the crystal on the carrier oscillator board. I was then able to bring the oscillator on frequency with C-6. I put the transmitter through some testing before I put the covers back on and I noticed that the carrier oscillator changes frequency when I turn the sideband switch. Upper sideband reads properly 5.645 MHZ and lower sideband reads 5.64453 MHZ. I would not have noticed this if I hadn't still had my freq counter plugged into the carrier osillator jack while switching sidebands. Any ideas what is going on here? Thanks, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Crystal Needed
Hi Guys, I have a T-4XC that has a carrier oscillator that C6 won't bring on frequency. Looks like I need a new crystal, eh? It looks like C6 is swinging the freq about 200hz but it is from 5644.55 to5644.33 or about 600hz low. When I turn on my transmitter it changes the R-4C freq noticeably. Is this most likely the crystal that has gone south? (literally) Could it be something else? Does someone have a basket case T-4XC that you don't mind stealing a crystal out for me? Is there a commercially available crystal for this old girl? I hate to buy another T-4XC just for the crystal! Thanks, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC Mystery
Hi Guys, About a month ago I was in a CW QSO using my C-line twins. While transmitting I was getting a little long winded, nothing outrageous, my transmission lasted maybe 1.5 minutes at the most when a quite visible puff of smoke arose from the T-4XC and the panel lights went out. Every thing was dead. I have been fairly busy lately and only now have I had a chance to try and figure out what happened. I opened up the T-4XC and did a visual check top and bottom and could find no discolored or burnt components. I checked the AC-4 and the main fuse (5 amp slo blo) was blown. I replaced the fuse and checked the power supply voltages everything was fine. I put the transmitter on a dummy load and it loads up fine. The power out seems a little light. It seems like I need an awful lot of plate current (nearly 400ma) to get over 100 watts on 40 meters. I didn't keep it at that plate current for very long. I did notice that the neutralization is off a bit. I guess I should do a voltage check and a complete alignment as it hasn't been done in a while. But I am not sure where to start looking for the origin of the smoke. Any ideas as to where I should start looking? Thanks in advance, Bob K6GGO P.S. the 15 ohm cathode resistors are fine ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Mystery
Hi Gary, Thanks! That was it. R59 fried and in two pieces. I just couldn't see it because it was still in position and appeared to be one piece. No 3.3 ohm resistors in the junk box so I will place an order in the AM. Maybe I will put a 1 watter in there just to increase the margin. Your service CD just paid for itself by saving me time searching for R59. Thanks Again Garey, Bob K6GGO Bob - First thing to check is R59. It has probably gone up in value, causing your meter to read high, and may even be the source of your smoke. Possible heater-cathode short in one of the Final tubes. Also check R132 and R133. You may have had a momentary short from one of the panel lamp socket lugs to chassis. They turn on the socket and can touch the chassis. Beyond that would take a little more investigation. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Robert Fish wrote: Hi Guys, About a month ago I was in a CW QSO using my C-line twins. While transmitting I was getting a little long winded, nothing outrageous, my transmission lasted maybe 1.5 minutes at the most when a quite visible puff of smoke arose from the T-4XC and the panel lights went out. Every thing was dead. I have been fairly busy lately and only now have I had a chance to try and figure out what happened. I opened up the T-4XC and did a visual check top and bottom and could find no discolored or burnt components. I checked the AC-4 and the main fuse (5 amp slo blo) was blown. I replaced the fuse and checked the power supply voltages everything was fine. I put the transmitter on a dummy load and it loads up fine. The power out seems a little light. It seems like I need an awful lot of plate current (nearly 400ma) to get over 100 watts on 40 meters. I didn't keep it at that plate current for very long. I did notice that the neutralization is off a bit. I guess I should do a voltage check and a complete alignment as it hasn't been done in a while. But I am not sure where to start looking for the origin of the smoke. Any ideas as to where I should start looking? Thanks in advance, Bob K6GGO P.S. the 15 ohm cathode resistors are fine ___ 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
