Re: New owner for R7 with couple of question
Claudio,
I have a box of vintage semiconductors that I've recently inventoried, and in it are several 2N5109 transistors. I've had these parts on a shelf for 20+ years, so I'm confident they're not fakes. If you want some, please let me know.?
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Thanks,
Robin Midgett K4IDC
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Re: Can anybody help with a TR4C?
I got back to the TR4C today. I disassembled, completely cleaned and inspected the mode switch, found a couple of bent fingers and straightened them and cleaned the switch fully. I did get the AM Mode back, but the CW is still being evasive.? The problem definitely seems to be in the V-2 stage. I checked the voltages?and resistor values in that stage. Found some interesting things. Ran out of time this afternoon. I had a spare tube and changed it with no change. It still keys the cw for a split second then unkeys. The sidetone stays constant?while the key is down. the momentary cw creates a momentary bump on the wattmeter and dummy load. Obviously there is a voltage missing and some that are not correct.?? V2 back in that back corner?is such a nice spacious place to work!! Going to have to burn some more midnight oil on this one.
V-2 12AV6 voltages
pin?????? Measured?????? Spec
1 ???????? -18 v? RX????????? 0
??????????? -.73? TX??????????? -1.6
2????????? 0????????????????????? 13.0????
3????????? 11.8 AC??????????? 12.6 AC
4????????? 0????????????????????? 0
5????????? -.41 RX???????????? 0
??????????? -.57 TX ??????????? .9
6????????? 0????????????????????? 0
7????????? 239????????????????? 255? ? ??
On Mon, Mar 17, 2025 at 9:12?PM Terry WB0VQP via <TLNixon357= [email protected]> wrote: Thanks Gary! I have had the entire front panel off the radio in order to get to that S-2 and clean it.? Not to say I got it all clean and working. I was suspicious of that as well.?
This radio? belonged to our local club The Davenport Radio Amateur Club INC for many years.? It was in the basement shack of our President when lightning struck his power lines and set his house on fire.? The electrical panel was only a few feet from his shack.? The whole family almost died in the fire.?
Although it did not have any heat or fire damage, it was really smoked-up and had some water damage.? ?So a little at a time I am trying to restore it.? ?It was given to me by the President when our insurance company bought us two new rigs to replace this one and an Icom damaged by the fire.
The SSB TX was intermittent?on it, and I discovered the key jack had some corrosion around it and was not grounding properly when the key was unplugged. .? Cleaned that all up and it is reliably working on SSB, but would like to make it fully functional.??
I still have an R4B and T4XC twins and another TR4 here. I love this Drake equipment.
Thanks Again!
Terry WB0VQP
On Sun, Mar 16, 2025 at 7:58?PM Gary Follett via <xntrick1948= [email protected]> wrote: Shown in magenta on the attached schematic is the path the sidetone oscillator signal takes to get to the VOX tube, V19A, in order to key the relays. This tube amplifies that sidetone signal just like it would an audio signal from the microphone input. This is rectified by D5 and fed to the keying triode V19B.
My most likely bet is that the contacts on S2 are not making good contact so the sidetone is not getting to the grid of V19A.
Also, while the VOX sensitivity pot has no impact on the CW ¡°VOX¡±, the Anti-Vox and Delay do affect CW ¡°VOX". Try turning Anti-Vox all the way CCW to see if that is an issue since you do NOT need Anti-Vox on CW.
Gary
W0DVN
On Sun, Mar 16, 2025 at 2:56?PM Gary Follett via <xntrick1948= [email protected]> wrote: Can you answer the question I already asked, "Do you have steady sidetone when key is held down?¡±?
Gary
W0DVN On Mar 16, 2025, at 12:43?PM, Gary Follett via <xntrick1948= [email protected]> wrote:
Do you have steady sidetone when key is held down?
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I¡¯m at a place called CPC in HAUPPAUGE, NY. Been here for close to 3 years working from the 3T¡¯s to the 9T¡¯s. T stands for Tesla. I¡¯ve been doing RF for over 34 years at different companies all over Long Idland, NY.?I¡¯m almost 63.
Mark
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I see you know your way around!
I worked on NMR instruments, specifically the Varian XL-100, back in grad school, early 1970¡¯s. This was the first 100 MHz instrument! Of course it did not image bodies, it did chemical analysis.
Gary
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On Mar 20, 2025, at 12:10?PM, Mark N2DMI via groups.io <markkiziuk1@...> wrote:
I can probably try those experiments that you just mentioned possibly tonight when I come home from work.
?
I work on drivers and power amps all day long that go into MRI UNITS.
Mark
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I can probably try those experiments that you just mentioned possibly tonight when I come home from work.
?
I work on drivers and power amps all day long that go into MRI UNITS.
Mark
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There¡¯s always a first!
BTW I just bought another TR-4CW but it has the RIT. It should be arriving soon. So when I get it I will definitely see if that one does it too!
Mark
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I would not suggest live-pulling of the Jones plug! That could be a significant safety risk.
I meant that you should, with a clip lead or similar, short the wiper to grind before you pull the AC mains cord, to see if this kills the chirp.
BTW: Over the decades, I have had maybe 5 TR-4¡¯s of various versions and have never heard what you are experiencing.
Gary
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On Mar 20, 2025, at 11:19?AM, Mark N2DMI via groups.io <markkiziuk1@...> wrote:
Also to pull the jones plug off of the back of the rig to turn off the rig I feel is not a good idea.
Mark
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Also to pull the jones plug off of the back of the rig to turn off the rig I feel is not a good idea.
Mark
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Also to short out the wiper to ground as I am pulling out (whichever plug) you would not hear anything the reason being is that the little mouse sound, squeal sound or whatever only last for a fraction of a second. So by the time I remove the plug and quickly short the wiper to ground the sound would already be gone.
Mark
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So unplug the jones connector and not the AC cord.
if I would to remove the Jones connector on the back of the unit I believe you completely shut off all voltages going to the rig. If I just disconnect the AC line cord plug then I believe the caps in the power supply would still supply the rig voltages until the caps in the power supply discharge. It could be fractions of a second for it to discharge or it could take longer not sure.
last night when you told me to remove the plug I removed the AC cord from the wall.
Mark
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OK, two more things:
DO the same test but, as you unplug the power supply, short the wiper of the AF gain pot to ground.
Also, try normally shutting the radio off with the switch but in the AM mode position.
Gary
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On Mar 20, 2025, at 1:22?AM, Mark N2DMI via groups.io <markkiziuk1@...> wrote:
OK Gary I turned both gain and volume up to full blast and unplugged the rig and it does not make that noise.
Mark
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OK Gary I turned both gain and volume up to full blast and unplugged the rig and it does not make that noise.
Mark
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I forgot, the AF Gain pot is also the power switch. It¡¯s been around 15 years since I last saw a TR-4, 4, 4C etc.
So obviously the issue lies in the AF stage.
It would be an interesting diagnostic to leave the AF Gain up quite a bit and depower the radio by unplugging the AC line cord to the power supply to see if this affects loudness or other characteristic of the noise.
Gary
W0DVN
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On Mar 19, 2025, at 7:55?PM, Jim Shorney via groups.io <jimNU0C@...> wrote:
You don't turn your radios off from a power strip?
On Wed, 19 Mar 2025 17:35:59 -0700
"Mark N2DMI via groups.io" <markkiziuk1@...> wrote:
You only hear the sound when you turn the rig OFF! Varying the AF gain doesn't make sense. --
73
-Jim
NU0C
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Re: Drake TR-4CW no receive then plate current oscillates then rises and blows fuse
#TR4-c
Thanks for those kind words John. Initially when the rig was acting up I was so so close to just tossing it!
But the more I started troubleshooting the more I started learning about this rig, especially ?with all of the help I received from this site!?
Want to hear something else. I just bought my second TR4-CW but this one has RIT. So I plan on fixing up my first TR4-CW (with no RIT) and selling it. I¡¯m going to keep my second TR4-CW with RIT and put the BEST into it. Gotta go to sleep now.
73¡¯s Mark
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You don't turn your radios off from a power strip? On Wed, 19 Mar 2025 17:35:59 -0700 "Mark N2DMI via groups.io" <markkiziuk1@...> wrote: You only hear the sound when you turn the rig OFF! Varying the AF gain doesn't make sense. -- 73 -Jim NU0C
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You only hear the sound when you turn the rig OFF! Varying the AF gain doesn't make sense.
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And that's how I sound after you get a couple of beeahs into me...
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with Proton Mail secure email.
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On Wednesday, March 19th, 2025 at 7:20 PM, n4buq <n4buq@...> wrote: ... "and don't drive like my brother!"
Barry - N4BUQ
----- Original Message -----
From: "jerry-KF6VB" jerry@...
To: "DRAKE-RADIO" [email protected]
Cc: "Steve Wedge, W1ES/4 via groups.io" w1es@...
Sent: Wednesday, March 19, 2025 3:35:28 PM
Subject: Re: [DRAKE-RADIO] TR-4CW Click'n clack... Man I miss those guys.
- Jerry, KF6VB
On 2025-03-19 13:32, Steve Wedge, W1ES/4 via groups.io wrote:
This is starting to remind me of the old "Car Talk" radio show, when
the caller would describe the sounds their car was making :-)
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with Proton Mail [1] secure email.
On Wednesday, March 19th, 2025 at 1:17 PM, Mark N2DMI via groups.io
markkiziuk1@... wrote:
And it¡¯s not a bweep sound it¡¯s more of the sound of a mouse
when it makes a tiny squeak.
Mark Links:
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[1]
[2] /g/DRAKE-RADIO/message/83753
[3] /mt/111781399/243852
[4] /g/DRAKE-RADIO/post
[5] /g/DRAKE-RADIO/editsub/243852
[6]
/g/DRAKE-RADIO/leave/12260778/243852/767576506/xyzzy
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... "and don't drive like my brother!"
Barry - N4BUQ
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----- Original Message ----- From: "jerry-KF6VB" <jerry@...>
To: "DRAKE-RADIO" <[email protected]>
Cc: "Steve Wedge, W1ES/4 via groups.io" <w1es@...>
Sent: Wednesday, March 19, 2025 3:35:28 PM
Subject: Re: [DRAKE-RADIO] TR-4CW Click'n clack... Man I miss those guys.
- Jerry, KF6VB
On 2025-03-19 13:32, Steve Wedge, W1ES/4 via groups.io wrote:
This is starting to remind me of the old "Car Talk" radio show, when
the caller would describe the sounds their car was making :-)
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with Proton Mail [1] secure email.
On Wednesday, March 19th, 2025 at 1:17 PM, Mark N2DMI via groups.io
<markkiziuk1@...> wrote:
And it¡¯s not a bweep sound it¡¯s more of the sound of a mouse
when it makes a tiny squeak.
Mark
Links:
------
[1]
[2] /g/DRAKE-RADIO/message/83753
[3] /mt/111781399/243852
[4] /g/DRAKE-RADIO/post
[5] /g/DRAKE-RADIO/editsub/243852
[6]
/g/DRAKE-RADIO/leave/12260778/243852/767576506/xyzzy
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Guys, I'm learning a lot from you guys about the "idiosyncrasies" of this rig. In a couple weeks I'll be ready. Thanks!?
One thing that can affect how loud the radio sounds is the IF Gain adjustment on the 2nd IF/Audio board. The adjustment given in the service manual is vague. Too low and the radio will not be as loud as it should on weaker signals. I have seen it advised that the IF Gain simply be set to maximum but this will make your S-Meter very generous. I have found that for me the best compromise is to adjust it for 30uV = S9 after the DC alignment of the ACG/S-Meter is done. Absolute sensitivity does not change, just the amount of gain in the 5 MHz IF. If you are chasing weak signals on the high bands an RF preamp can help. You don't even need to worry about T/R switching an inline preamp, you can use the handy RX antenna loop on the back panel that was intended for use with an R7. You will of course need to cut the internal jumper between the two RX jacks to do this.
On Wed, 19 Mar 2025 14:02:35 -0700
"James? N8CAH via " <jimamos=[email protected]> wrote:
> One think I have noticed though is that the overall audio level seems low.? ?The radio in general has enough sensitivity, and the S-Meter and IF calibration looks good.? The radio just isn't? that loud.? So, perhaps one or more of the electrolytic caps in the AF chain are lossy.
--
73
-Jim
NU0C
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One thing that can affect how loud the radio sounds is the IF Gain adjustment on the 2nd IF/Audio board. The adjustment given in the service manual is vague. Too low and the radio will not be as loud as it should on weaker signals. I have seen it advised that the IF Gain simply be set to maximum but this will make your S-Meter very generous. I have found that for me the best compromise is to adjust it for 30uV = S9 after the DC alignment of the ACG/S-Meter is done. Absolute sensitivity does not change, just the amount of gain in the 5 MHz IF. If you are chasing weak signals on the high bands an RF preamp can help. You don't even need to worry about T/R switching an inline preamp, you can use the handy RX antenna loop on the back panel that was intended for use with an R7. You will of course need to cut the internal jumper between the two RX jacks to do this. On Wed, 19 Mar 2025 14:02:35 -0700 "James N8CAH via groups.io" <jimamos@...> wrote: One think I have noticed though is that the overall audio level seems low.? ?The radio in general has enough sensitivity, and the S-Meter and IF calibration looks good.? The radio just isn't? that loud.? So, perhaps one or more of the electrolytic caps in the AF chain are lossy. -- 73 -Jim NU0C
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Robin K4IDC
Mark N2DMI
Jim Shorney
Bob W4JFA