Re: R-4B: Garbled Audio on 40m
On Tue, Feb 20, 2024 at 06:47 PM, Yuichi DL1FYM wrote:
By slightly adjusting the preselector away from the usual setting
Well, don't do that.?? Hi Hi... You are probably using the PTO signal (or its harmonics) as the 1st mixer signal to actually receive on some frequency. With the proper crystal engaged and the Preselector set where it should be these extra signals should be pretty weak but if the signals are strong enough, they will come thorough.?? The problems of superhet radios in this class. By misadjusting the Preselector, you can receive WWV (US standard freq/time station) on both 5 and 10MHz without buying? more crystals, somewhat handy.? Other frequencies can be received as you have found. 73, Gary WB6OGD
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TR-4 PTO Power Connections
"Electronica"....I didn't see a real name anywhere.? Names and callsigns are appreciated here.
I have attached a couple of pics that show the power supply wires for the TR-4 PTO.? They are pretty much the same for the TR-4C/CW/CW-rit, except the board is glass epoxy on the later series.? "Board 1" (those of us with K4OAH's Service CD's know what that means!) is where the red/white wire from the PTO attaches to a terminal near the front end of the xcvr.? With the radio upside down and facing you, it is on the left side and nearest to you, just to the left of the RV-4 accessory socket.? It is the second terminal "down" on Board #1 from the bottom of the radio...I am assuming your radio is upside down at this point.? There should be TWO red/white wires attached there.? One goes from there through the hole in the chassis to the PTO, while the other goes to the turret on the bottom of V20 (the OA2 regulator) just behind the audio transformer and is attached to the upper end (with radio still upside down) of power resistor R140. There should be?+11 VDC on the resistor at the red/white wire end, and of course +11 VDC on the terminal on Board #1 where both the the red/white wires are attached.
Remember.... that as you have a TR-4C and not a TR-4, it does look a bit different....but not much!
73 Peter VE7PS
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Re: R-4B: Garbled Audio on 40m
I have two instances of the R-4C (6HS6 + 6EJ6 mixer) and one R-4B. Each unit exhibits a form of overload on the 40-meter band during the evening when continental broadcast stations become particularly strong. This phenomenon can be confirmed by switching to AM mode and selecting the extra crystal switch to an unoccupied channel. By slightly adjusting the preselector away from the usual setting for the 40-meter band, multiple robust broadcast stations become audible in AM mode. Although this issue can be mitigated to some extent by carefully adjusting the band coils, I continue to experience it in my setup. Adding attenuator in front of antenna input will help a lot, too.
Yuichi, JJ1IGT
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Re: Drake Owners in Dallas TX?
Hi Chris.
Yes. I can help.?
I'm in Richardson.?
Good on QRZ.
73
Bob
WB9RHW?
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Drake Owners in Dallas TX?
New member here¡. I recently acquired a Drake TR4 ¨C CW and AC-4 power supply. ?However, I¡¯m not able to get the initial bias current to .1 A and a few other things that don¡¯t seem right when tuning into a dummy load.
The rig does power up and receives CW and SSB.
?
Looking for someone who¡¯s willing to help me test the rig with a known good power supply, and to test the power supply with a known good rig to help me rule out where the potential problem might be.
?
Chris, DE ?WX7V
?
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Many thanks for the correlation, Richard.
I have the manual - and the CDs,
so, despite scary synaptic deceleration,
I should be able to reivive my R4-B.
It would be sacrilege to abandon it...
I learn a lot - and save many files from this group
for reference.
Michael 2E0IHW
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On 20/02/2024 20:09, Richard Knoppow wrote: ?? In the R-4B handbook. See pages 35 and 37. P.35 is the procedure for setting the AVC/S-meter, p.37 is a photo of the underside of the chassis showing the locations of adjustments.
??? Note that there is a Zero adjustment on the side of the chassis. Setting the S-meter is somewhat inconvenient because the chassis must be upright and level to keep the pointer in the right place, making some adjustments hard to get to. However, the adjustments are pretty stable and once set usually don't have to be touched for a long time.
?? If not already mentioned in this thread be aware that the AVC is very sensitive to gassy tubes. If it doesn't set up right or the time constants are way off the problem is often a gassy tube. These tube check OK on tube checker gas tests so substituting is the only reliable way to trouble shoot. I don't remember which are the most common problems but someone else here probably does.
?? Also, if you do not have Garry Barrel's CD for the B line I strongly advise you to get it. It has much information in it which is not available elsewhere including high resolution photos of chassis and a parts finder. Gary is SK but his wife still sells the CD's, someone else will have to give you the URL.
On 2/20/2024 11:52 AM, Michael.2E0IHW via groups.io wrote:
Must have missed something....
I would like to get my R4-B near-pristine ...
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ok, i hope you images, many thanks
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Re: R-4B: Garbled Audio on 40m
I am mostly familiar with the R4B, which might be very different from the 2B. I found the most useful tool for adjusting the slugs in the PBT is an alligator clip. It allows me to turn the slug wire but not have any backlash.
Be aware that the slugs will pull in and out causing the adjustment to be way off. The clip allows moving it to where it belongs.
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On 2/20/2024 7:42 AM, Steve Wedge, W1ES/4 via groups.io wrote: It¡¯s cool what we found on the various 2-B¡¯s we worked on last year. I had two other ones besides that horrorshow.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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In the R-4B handbook. See pages 35 and 37. P.35 is the procedure for setting the AVC/S-meter, p.37 is a photo of the underside of the chassis showing the locations of adjustments.
Note that there is a Zero adjustment on the side of the chassis. Setting the S-meter is somewhat inconvenient because the chassis must be upright and level to keep the pointer in the right place, making some adjustments hard to get to. However, the adjustments are pretty stable and once set usually don't have to be touched for a long time.
If not already mentioned in this thread be aware that the AVC is very sensitive to gassy tubes. If it doesn't set up right or the time constants are way off the problem is often a gassy tube. These tube check OK on tube checker gas tests so substituting is the only reliable way to trouble shoot. I don't remember which are the most common problems but someone else here probably does.
Also, if you do not have Garry Barrel's CD for the B line I strongly advise you to get it. It has much information in it which is not available elsewhere including high resolution photos of chassis and a parts finder. Gary is SK but his wife still sells the CD's, someone else will have to give you the URL.
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On 2/20/2024 11:52 AM, Michael.2E0IHW via groups.io wrote: Must have missed something....
I would like to get my R4-B near-pristine ...
para 6.4.9 with fig. 13 - where to be found, please?
Michael 2E0IHW
On 20/02/2024 14:56, Mark - WB0IQK wrote:
...
The procedure you want to follow is paragraph 6.4.9 then look at Figure 13 and you will see at the bottom the RCV SENS
Mark, WB0IQK
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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Must have missed something....
I would like to get my R4-B near-pristine ...
para 6.4.9 with fig. 13 - where to be found, please?
Michael 2E0IHW
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On 20/02/2024 14:56, Mark - WB0IQK wrote: ... The procedure you want to follow is paragraph 6.4.9 then look at Figure 13 and you will see at the bottom the RCV SENS
Mark, WB0IQK
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Re: R-4B: Garbled Audio on 40m
The ends are intentionally flattened so that they can be torqued.
I have had much better luck using an "internal" tweaker: basically an adjustment tool with the flat blade inside the plastic outer rod.? This is what you see with the Bourns trimmer but the blade goes deeper into the body.
Getting the adjustment right may require you to input enormous signals (millivolts) into the receiver but that will work to allow you to see which of the four adjustments is off.
Movement of the slugs, in and out of their coils, is less than 1/8".? Disassembly of the slug rack reveals how the whole thing works and it's rather ingenious.? There is a disc of varying thickness that rotates and moves the slugs in and out of their forms.? The setting of that screw on the back moves the whole assembly to the optimum point, together.? That, basically, allows you to centre the assembly.
There is a detailed schematic of the PBT assembly that comes with Garey's CD's/files but I believe it it's also up on Ron's website.
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Tuesday, February 20th, 2024 at 1:28 PM, Lyman via groups.io <forum4ll@...> wrote:
[Edited Message Follows]
Gary, thanks for the photo. I'm fortunate that the rods are not bent but they are mashed from the use of pliers. I plan to use an X-acto pin vise to grab the rod to turn. The use of pliers to adjust anything bothers me. Looking forward to this when Ii get back to the shop tomorrow.
--
Lyman Lew
KK6LPW
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Re: R-4B: Garbled Audio on 40m
Gary, thanks for the photo. I'm fortunate that the rods are not bent but they are mashed from the use of pliers. I plan to use an X-acto pin vise to grab the rod to turn. The use of pliers to adjust anything bothers me. Looking forward to this when Ii get back to the shop tomorrow.
--
Lyman Lew
KK6LPW
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Re: Drake TR-7 - A repair journey
Awseome! I'm glad you got it up and running. Another prodigal child returns to the flock. I feel your pain, my local noise floor has increased dramatically in recent years. On 80m particularly, S-9+ although Clipperton was heard through it on CW. Tell us about your DF loop. :) 73 -Jim NU0C On Tue, 20 Feb 2024 09:20:19 -0800 "atlasstuff" <g4fph@...> wrote: Jim,
I added a 68 R in series with the existing R2303 (which was 47 R). That brought the driver standing current down to about 220 mA, which seems reasonable to me and is more in line with your note. At max RF out, the driver DC current peaks to around 700 mA, so nine and a bit Watt going in.
As with the rest of this TR-7, I am not the first to crack open the PA brick. The final devices are MRF421, with a 1990 date code, which is great. The driver transistors had been changed at least once prior to my putting Japanese ones in.
I did the ALC mod. and added the HPF ground strap, followed by an alignment and screwed the screening plates back in place, but not yet put the covers back on;-)
Imagine my joy to find most of HF to be covered by some new, pulsing, buzzing interference:-( Out with the DF loop tomorrow, I think. Be nice to get some fresh air after all the solder smoke - HI!
Regards,
Mark, G4FPH.
-- 73 -Jim NU0C
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Re: Drake TR-7 - A repair journey
Jim,
I added a 68 R in series with the existing R2303 (which was 47 R). That brought the driver standing current down to about 220 mA, which seems reasonable to me and is more in line with your note. At max RF out, the driver DC current peaks to around 700 mA, so nine and a bit Watt going in.
As with the rest of this TR-7, I am not the first to crack open the PA brick. The final devices are MRF421, with a 1990 date code, which is great. The driver transistors had been changed at least once prior to my putting Japanese ones in.
I did the ALC mod. and added the HPF ground strap, followed by an alignment and screwed the screening plates back in place, but not yet put the covers back on;-)
Imagine my joy to find most of HF to be covered by some new, pulsing, buzzing interference:-( Out with the DF loop tomorrow, I think. Be nice to get some fresh air after all the solder smoke - HI!
Regards,
Mark, G4FPH.
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The 11volts comes from a big wirewound dropping resistor from the 150V.? See the schematic and look for the resistor.
Hopefully they didn't remove it for the previous mods.
73,
Gary
WB6OGD
?
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Re: R-4B: Garbled Audio on 40m
It¡¯s cool what we found on the various 2-B¡¯s we worked on last year. I had two other ones besides that horrorshow.?
One of the others sounded obviously like the PBT needed adjustment, so I finally figured how to do it without removing the slug rack. I have a full set of those D-C adjustment tools and there are a couple ?that are short enough where I can get them in there.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 20, 2024 at 10:23, Gary WB6OGD < winbladgary@...> wrote: Yes Steve, the one with the glue inside for lubrication, hi hi...
It had to come apart for that anyway.
73,
Gary
WB6OGD
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Hmmm. ?On two different transmitters, with a diverse collection of mics¡
Did you do alignments on both? ?I¡¯m trying to find a common thread.?
How is the carrier balance? ?I set carrier balance with an oscilloscope, which is much easier than their plate current procedure.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 20, 2024 at 10:06, Mark KF0KZP < fleischtpnl@...> wrote: I will put up some pictures of my setup and what it looks like on my other radios later tonight when i get home or tomorrow morning. Thanks for the help.
Mark
On Tue, Feb 20, 2024 at 8:55?AM Mark KF0KZP via <fleischtpnl= [email protected]> wrote: Both. I have listened on a couple different radios I have and have seen the signal on the waterfall on those radios. I have also gotten a report back from another Ham who said there was to much RFI(noise) that he could hear me but it was so noisy. When I key the mic in SSB the signal(on my other radios looks good but when I apply any audio the signal spreads out across both sides of the carrier(which isn't there for SSB) but looks almost the same as transmitting on AM. Which again when I switch over to transmit in AM it sounds good. The distortion sounds (I know not technical) like when you are tuning in a signal and you go from the high pitch past the good signal to the lower pitch. I have run it through a manual tuner Drake RC-4 and through an automatic antenna tuner. It is also the same if I run it into a dummy load or into an antenna. I have read through the manuals and have watched some videos on YouTube and seem to be doing everything correctly. Again, I'm hoping it is something simple that I'm missing. Thanks for the help.
Mark
On Mon, Feb 19, 2024 at 7:34?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Mark, when you say you're distorted on SSB, is that your monitoring on another receiver or are others saying that your signal sounds distorted?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Monday, February 19th, 2024 at 6:38 PM, Mark KF0KZP < fleischtpnl@...> wrote:
I am new to collecting Drake radios but so far love the radios. I have a R-4C & T-4xc(combo) and I also have a TR-4. I am having the same issues with both so I am obviously doing something wrong. Receiving is working fine on the C-Line and the TR-4. I can also tune both of them as per manuals. They are both putting out power on all bands. CW seems to work fine and AM is clear when transmitting but on both when on SSB the signal is distorted and a lot of RFI. I have tried the Heil AD-1-C with the Pro-7 Headphones and also a Shure SM7B microphone. Then I talked to one of the engineers at Heil and I purchased the CC-1-C cable and the Gold Elite Vintage microphone and have the same issues. What am I missing and where should I start? Thanks for the help and look forward to hearing some things I should try.
Mark
KF0KZP
--
Mark "Fleisch" Fleischer KF?KZP 
Public Address Announcer/Voice Over/Production Specialist:
, , , , , , (Superior), and (Proctor)
--
Mark "Fleisch" Fleischer KF?KZP
Public Address Announcer/Voice Over/Production Specialist:
, , , , , , (Superior), and (Proctor)
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It¡¯s a TR-4.?
Yeah, I do this, too. Don¡¯t feel bad, Mark :-)
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 20, 2024 at 09:56, Mark - WB0IQK < mgilger@...> wrote: Joel,
I would look again for the pot. All R4B's have it. Even the earlier R4A and R4's.
The procedure you want to follow is paragraph 6.4.9 then look at Figure 13 and you will see at the bottom the RCV SENS
Good luck,
Mark, WB0IQK
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Dean - You have done an awesome restoration on your 2B; super congratulations on what you have done.? The front panel looks just like Drake made it.....minus the original knobs....however, yours looks terrific.? I have a 2B, original...yours look 'almost' better than mine.? Well done sir!?? 73, Larry KC8JX
On Tuesday, February 20, 2024 at 09:35:49 AM EST, K5DH via groups.io <mustang_maniac@...> wrote:
I bought a restorable 2B with 2AC off Craigslist last year from a fellow ham in Florida for $50 plus shipping.? It did not require any unusual work to get it going.? I replaced a couple of weak tubes, replaced all of the electrolytic caps, touched up the alignment, replaced the missing 100 KHz calibrator crystal, and installed a 3-wire line cord for safety.? That was all it took to make it work right.? While I had it on the bench, I removed the front panel, cleaned it with soap and water, then used a mild automotive polishing compound to remove paint oxidation and bring up the shine.? I have since added crystals for 30 meters and the "A" segment of 10 meters using the little HC-49 crystals installed in HC-6 holders.? When I received the 2B the only original Drake knob it had was the FREQUENCY knob.? The rest were old generic knobs out of someone's junkbox.? I installed a matching set of modern aluminum knobs purchased off eBay.? They don't look "right" but they don't look bad, and they'll do until I can find the correct knobs.?  73, Dean K5DH
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Re: R-4B: Garbled Audio on 40m
Yes Steve, the one with the glue inside for lubrication, hi hi...
It had to come apart for that anyway.
73,
Gary
WB6OGD
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Gary WB6OGD
Yuichi DL1FYM
Bob Tragesser
Chris - WX7V
Lyman
Jim Shorney