Re: TR-4C low power output on 15 & 10 meters
And it¡¯s not as important to have exactly matched tubes but it is important that they all be the same brand.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 14:23, Dave W7GZ via groups.io < w7gz@...> wrote:
Dave, a quick review of eBay shows several 6JB6/6JU6 going for around $15 NIB + shipping. Perhaps you can find someone with 3 for sale.
?
Dave
|
Re: TR-4C low power output on 15 & 10 meters
6GJ5 tubes have been used as a less expensive alternative. ?Do a search and you¡¯ll find some info and can decide if you want to try them.
|
Re: TR-4C low power output on 15 & 10 meters
Dave, a quick review of eBay shows several 6JB6/6JU6 going for around $15 NIB + shipping. Perhaps you can find someone with 3 for sale.
?
Dave
|
Re: TR-4C low power output on 15 & 10 meters
Yes, I failed to mention that. BIAS is at 0.1 amp.
So, sounds like everyone agrees, it's the finals. That is an easy fix! But rather expensive. Where are folks finding the best deal on new finals?
73, Dave KD5FX
?
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Re: Drake R4/T4 rubber feet machine screws
Mike is right about the AC-4 small rubber feet?with the stud at 6-32.
Steve is right about the 10-24 screw for the large plastic feet.
PS
Steve and the group
those small rubber feet that screw into the bottom of the AC4 are in fact 6-32 thread. You can get the rubber feet from McMaster Carr, although I don¡¯t remember the part number off the top of my head
On Feb 4, 2025, at 12:16 PM, Steve Wedge, W1ES/4 via < w1es@...> wrote:
Pretty sure it¡¯s 10-24.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 10:40 AM, Scott N1IA via?<soakland5@...> wrote:I am trying to get some machine screws for the rubber feet of the Drake R4 / T4. What size do I need??
Thanks guys, Scott N1IA
|
Re: Drake R4/T4 rubber feet machine screws
Yup - 10-24 Common Slot Pan Head IF you want originality.? I can get the?length for you later today.? 1/2" or 5/8" sounds about right.
73 PS
On Tue, Feb 4, 2025 at 9:16?AM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Pretty sure it¡¯s 10-24.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 10:40 AM, Scott N1IA via < soakland5@...> wrote:
I am trying to get some machine screws for the rubber feet of the Drake R4 / T4. What size do I need?
Thanks guys,
Scott N1IA
|
Re: TR-4C low power output on 15 & 10 meters
If you have confirmed that your idle current is 100mA then I would agree that your finals are tired.
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Re: TR-4C low power output on 15 & 10 meters
Ok, my readings compensating T9 de-tuning
on 10m. All relatives, of course.
10m 30V 400mA 105W
15m 27V 420mA 135W
20m 28V 390mA 165W
See that with more or less the same "p-p drive level" I got higher
plate current (and higher output pwr).
Note that I modified the wiring around external RX switch: so when
I connect the scope there, there is not any extra coaxial run
between switch and antenna relay (less parallel C).
Seems that up to the 12BY7 things are ok. May be the finals
reached EOL.
73
Marcus PY2PLL.
Em 04/02/2025 13:12, Dave KD5FX via
groups.io escreveu:
toggle quoted message
Show quoted text
This is the same TR-4C that had the bad Xtals which were
fixed by a baking. The problem now is the output is very low on
15 and 10 meters. Someone suggested I test the output on each
band at the output of T9 which is on the driver. So I did and
here is the results. Also, I re-tested the driver tube and the
final, they all checked very good and I did a resistance test on
the driver and finals as per the readings in the manual and they
were all good.
Band? ?T9 out Power out
80? ? ? ?35V? ? ?130 W @ 0.4 amps
40? ? ? ?28V? ? ? ?90 W @ 0.375 amps
20? ? ? ?27V? ? ? 100 W @ 0.5 amps
15? ? ? ?35V? ? ? ? 30 W? @ 0.25 amps
10-1? ?30V? ? ? ? ? 5 W? @ 0.2 amps
10-2? ?30V? ? ? ? ? 5 W? @ 0.2 amps
10-3? ?30V? ? ? ? ? 5 W? @ 0.2 amps
There may have been some de-tuning from the scope probe in
the circuit, I get about 25 W output on 10 without the probe
there.?
I have checked and double checked all the fingers on the band
switch.?
What should I look at next? Some component is out of spec
somewhere.
|
Re: TR-4C low power output on 15 & 10 meters
They are not new, but they test OK, about mid-way on the output scale. Is it not a valid way to test final tubes?
73, Dave
|
Re: Drake R4/T4 rubber feet machine screws
Steve and the group
those small rubber feet that screw into the bottom of the AC4 are in fact 6-32 thread. You can get the rubber feet from McMaster Carr, although I don¡¯t remember the part number off the top of my head
toggle quoted message
Show quoted text
On Feb 4, 2025, at 12:16 PM, Steve Wedge, W1ES/4 via < w1es@...> wrote:
Pretty sure it¡¯s 10-24.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 10:40 AM, Scott N1IA via?<soakland5@...> wrote:I am trying to get some machine screws for the rubber feet of the Drake R4 / T4. What size do I need??
Thanks guys, Scott N1IA
|
Re: The mysteriously modified 7077 (and nothing else¡)
I believe the latest manual, available at WB4HFN, shows the pinout for the two mic inputs.
Thanks, Evan. ?It is a TR7A, so perhaps I¡¯ll do some experimentation.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 10:09 AM, Evan via groups.io < k9sqg@...> wrote:
Yes for the TR-7A and possibly late production TR-7. ?One pin is for "high output high impedance" while the other is "low output low impedance"; ?basically just a resistor between the two pins. ?
Indeed.?
I thought I¡¯d heard that there are two audio inputs to the TR7. I¡¯m going to have to look at the service manual, as the owner¡¯s manual only shows pin 4 as n/c. Perhaps this low level element could directly feed the low-level input, if it exists¡
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 08:01, James Barrie via groups.io <
barrie43@...> wrote:
What a mess
Point taken. I haven¡¯t spent much on radio lately, so I owe it to myself :-D
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Mon, Feb 3, 2025 at 20:47, Jim Shorney via
<
jimNU0C@...> wrote:
I hate to say it but you might be better off with the Heil cartridge. In my mic comparison runs, the 7077 cam in dead last behind various vintage Shure, Turner, E-V, and modified D-104/UGxx microphones for audio quality.
On Tue, 04 Feb 2025 01:36:40 +0000
"Steve Wedge, W1ES/4 via
" <w1es=
[email protected]> wrote:
> If I have to, I can install a Heil kit and know that I will have a good mic. But if I can regain the performance without spending another $70, I¡¯m good with that.
--
73
-Jim
NU0C
|
Re: TR-4C low power output on 15 & 10 meters
These are not new finals, correct? This appears to be finals that are at their end of life.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 11:12 AM, Dave KD5FX via groups.io < land.dave@...> wrote:
This is the same TR-4C that had the bad Xtals which were fixed by a baking. The problem now is the output is very low on 15 and 10 meters. Someone suggested I test the output on each band at the output of T9 which is on the driver. So I did and here is the results. Also, I re-tested the driver tube and the final, they all checked very good and I did a resistance test on the driver and finals as per the readings in the manual and they were all good.
Band? ?T9 out Power out
80? ? ? ?35V? ? ?130 W @ 0.4 amps
40? ? ? ?28V? ? ? ?90 W @ 0.375 amps
20? ? ? ?27V? ? ? 100 W @ 0.5 amps
15? ? ? ?35V? ? ? ? 30 W? @ 0.25 amps
10-1? ?30V? ? ? ? ? 5 W? @ 0.2 amps
10-2? ?30V? ? ? ? ? 5 W? @ 0.2 amps
10-3? ?30V? ? ? ? ? 5 W? @ 0.2 amps
There may have been some de-tuning from the scope probe in the circuit, I get about 25 W output on 10 without the probe there.?
I have checked and double checked all the fingers on the band switch.?
What should I look at next? Some component is out of spec somewhere.
|
Re: Drake R4/T4 rubber feet machine screws
Pretty sure it¡¯s 10-24.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 10:40 AM, Scott N1IA via groups.io < soakland5@...> wrote:
I am trying to get some machine screws for the rubber feet of the Drake R4 / T4. What size do I need?
Thanks guys,
Scott N1IA
|
Re: The mysteriously modified 7077 (and nothing else¡)
Thanks, Evan. ?It is a TR7A, so perhaps I¡¯ll do some experimentation.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 10:09 AM, Evan via groups.io < k9sqg@...> wrote:
Yes for the TR-7A and possibly late production TR-7. ?One pin is for "high output high impedance" while the other is "low output low impedance"; ?basically just a resistor between the two pins. ?
Indeed.?
I thought I¡¯d heard that there are two audio inputs to the TR7. I¡¯m going to have to look at the service manual, as the owner¡¯s manual only shows pin 4 as n/c. Perhaps this low level element could directly feed the low-level input, if it exists¡
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 08:01, James Barrie via groups.io <
barrie43@...> wrote:
What a mess
Point taken. I haven¡¯t spent much on radio lately, so I owe it to myself :-D
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Mon, Feb 3, 2025 at 20:47, Jim Shorney via
<
jimNU0C@...> wrote:
I hate to say it but you might be better off with the Heil cartridge. In my mic comparison runs, the 7077 cam in dead last behind various vintage Shure, Turner, E-V, and modified D-104/UGxx microphones for audio quality.
On Tue, 04 Feb 2025 01:36:40 +0000
"Steve Wedge, W1ES/4 via
" <w1es=
[email protected]> wrote:
> If I have to, I can install a Heil kit and know that I will have a good mic. But if I can regain the performance without spending another $70, I¡¯m good with that.
--
73
-Jim
NU0C
|
Mike, thank you for your thoughts.? Your first paragraph mirrors my thoughts exactly. ? I don¡¯t have much test equipment other than VOM but I can get a can of contact cleaner and deoxit as well as reseating the crystals. ? Tony... WB8ZWI WRQJ370 ? Sent from my Compuserve Account ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Mike Bryce via groups.io
Sent: Tuesday, February 4, 2025 9:48 AM
To: [email protected]
Subject: Re: [DRAKE-RADIO] TR22C Repair? °Õ´Ç²Ô²â¡. Geeze, I don¡¯t want to pop your cork, but the bench time, lack of parts, and when you¡¯re done, you have a heavy 1W fixed freq transceiver with no PL tones for repeater access. I have about a dozen of these in the shop, from TR22, to TR33C including the Kenwood variants.? I have a TR33C that lives in the kitchen, and on friday nights, I check into the local repeater net. I¡¯m within the shadow of the repeater tower, so the 1W works fine. I was picking up these radios as hamfests for $20 and under. I usually purchased them if I needed a crystal for one that I had. Now that being said, I have now noticed that the asking price for these has went out of control, and for the life of me I can¡¯t understand it. Check to see if the crystal oscillator is running. Old crystals sometimes won¡¯t fire. Reset and clean the crystal¡¯s pins. You should hear a change in the static when you insert a crystal into its socket. No change means there¡¯s an issue with either the crystal of the oscillator. The ceramic filters go bad, and there are no replacements except for a parts radio. And of course always fall back with ¡®clean the contacts with deoxit.¡¯? ?
On Feb 4, 2025, at 9:34 AM, Tony WB8ZWI via <tfiorda@...> wrote: ? Hello all!? I've been going through my old 2m radios thinking I might sell them but not wanting to sell a broken one.? I have a couple of TR22C's.? One was my fathers and the other was mine.? We used them for a few years when we got in the hobby prior to switching to some HTs (IC2AT) with VFOs.? In any case that is another story.??
One of the radios seems to have a receive issue.? I only get noise and static when I power it up.? It does transmit, at least according to my external RF meter and the vu meter on the radio itself. The only mods might be a light behind the dial (which isn't lighting, so I am not sure I remember) to indicate what channel it's on and the earphone plug was modified to accept a standard DTMF pad from a touchtone phone. (Good old autopatch days!) I am trying to find out is someone or someplace still repairs these.? I am located just outside of Dallas, TX.? I am willing to ship for the repair.? Any help would be appreciated.??
?
|
TR-4C low power output on 15 & 10 meters
This is the same TR-4C that had the bad Xtals which were fixed by a baking. The problem now is the output is very low on 15 and 10 meters. Someone suggested I test the output on each band at the output of T9 which is on the driver. So I did and here is the results. Also, I re-tested the driver tube and the final, they all checked very good and I did a resistance test on the driver and finals as per the readings in the manual and they were all good.
Band? ?T9 out Power out
80? ? ? ?35V? ? ?130 W @ 0.4 amps
40? ? ? ?28V? ? ? ?90 W @ 0.375 amps
20? ? ? ?27V? ? ? 100 W @ 0.5 amps
15? ? ? ?35V? ? ? ? 30 W? @ 0.25 amps
10-1? ?30V? ? ? ? ? 5 W? @ 0.2 amps
10-2? ?30V? ? ? ? ? 5 W? @ 0.2 amps
10-3? ?30V? ? ? ? ? 5 W? @ 0.2 amps
There may have been some de-tuning from the scope probe in the circuit, I get about 25 W output on 10 without the probe there.?
I have checked and double checked all the fingers on the band switch.?
What should I look at next? Some component is out of spec somewhere.
|
°Õ´Ç²Ô²â¡.
Geeze, I don¡¯t want to pop your cork, but the bench time, lack of parts, and when you¡¯re done, you have a heavy 1W fixed freq transceiver with no PL tones for repeater access.
I have about a dozen of these in the shop, from TR22, to TR33C including the Kenwood variants.?
I have a TR33C that lives in the kitchen, and on friday nights, I check into the local repeater net. I¡¯m within the shadow of the repeater tower, so the 1W works fine.
I was picking up these radios as hamfests for $20 and under. I usually purchased them if I needed a crystal for one that I had.
Now that being said, I have now noticed that the asking price for these has went out of control, and for the life of me I can¡¯t understand it.
Check to see if the crystal oscillator is running. Old crystals sometimes won¡¯t fire. Reset and clean the crystal¡¯s pins. You should hear a change in the static when you insert a crystal into its socket. No change means there¡¯s an issue with either the crystal of the oscillator. The ceramic filters go bad, and there are no replacements except for a parts radio.
And of course always fall back with ¡®clean the contacts with deoxit.¡¯?
toggle quoted message
Show quoted text
On Feb 4, 2025, at 9:34 AM, Tony WB8ZWI via < tfiorda@...> wrote:
Hello all!? I've been going through my old 2m radios thinking I might sell them but not wanting to sell a broken one.? I have a couple of TR22C's.? One was my fathers and the other was mine.? We used them for a few years when we got in the hobby prior to switching to some HTs (IC2AT) with VFOs.? In any case that is another story.??
One of the radios seems to have a receive issue.? I only get noise and static when I power it up.? It does transmit, at least according to my external RF meter and the vu meter on the radio itself. The only mods might be a light behind the dial (which isn't lighting, so I am not sure I remember) to indicate what channel it's on and the earphone plug was modified to accept a standard DTMF pad from a touchtone phone. (Good old autopatch days!)
?
I am trying to find out is someone or someplace still repairs these.? I am located just outside of Dallas, TX.? I am willing to ship for the repair.? Any help would be appreciated.??
?
Thanks,
Tony...
|
Drake R4/T4 rubber feet machine screws
I am trying to get some machine screws for the rubber feet of the Drake R4 / T4. What size do I need?
Thanks guys,
Scott N1IA
|
Re: The mysteriously modified 7077 (and nothing else¡)
Yes for the TR-7A and possibly late production TR-7. ?One pin is for "high output high impedance" while the other is "low output low impedance"; ?basically just a resistor between the two pins. ?
Indeed.?
I thought I¡¯d heard that there are two audio inputs to the TR7. I¡¯m going to have to look at the service manual, as the owner¡¯s manual only shows pin 4 as n/c. Perhaps this low level element could directly feed the low-level input, if it exists¡
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Tue, Feb 4, 2025 at 08:01, James Barrie via groups.io < barrie43@...> wrote: What a mess
Point taken. I haven¡¯t spent much on radio lately, so I owe it to myself :-D
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Mon, Feb 3, 2025 at 20:47, Jim Shorney via
<
jimNU0C@...> wrote:
I hate to say it but you might be better off with the Heil cartridge. In my mic comparison runs, the 7077 cam in dead last behind various vintage Shure, Turner, E-V, and modified D-104/UGxx microphones for audio quality.
On Tue, 04 Feb 2025 01:36:40 +0000
"Steve Wedge, W1ES/4 via
" <w1es=
[email protected]> wrote:
> If I have to, I can install a Heil kit and know that I will have a good mic. But if I can regain the performance without spending another $70, I¡¯m good with that.
--
73
-Jim
NU0C
|
Has anyone done a sensitivity / selectivity test between a R4B VS a R4C?
Bill N1WL
On Monday, February 3, 2025 at 08:26:57 PM EST, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
I prefer the C in tight quarters on CW. You can get crystal filters down to 250 Hz stock and 125 Hz if you search. In pileups, these are the equal to newer rigs¡¯ receivers.?
For everyday, casual CW, the B sounds quite nice.?
Understand that the shape factors of the two rigs¡¯ filters are fairly different. Some prefer one over the other.?
The CW subbands aren¡¯t as crowded as they were 20 years ago, so take that into consideration.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Mon, Feb 3, 2025 at 15:17, Craig W8CS via groups.io < craig_severson@...> wrote:
Hi Scott, have you read the VE3EFJ "Drakemod" manifesto? If I recall Wayne's verbiage, it's something like this:
?
The R-4B is a terrific receiver out of the box and it does everything well, however you won't get the selectivity of an R-4C. The R-4C stock is a bit of a waste compared to its potential due to some questionable design choices. A properly (Sherwood) modified R-4C is transformed and is an exceptional receiver.?
?
Others will have a much more technical take than mine. The 4B is great out of the box; the 4C requires some work to realize exceptional potential.?
--
Craig/W8CS
Greenville, SC
|
Marcus PY2PLL
Tony WB8ZWI
Scott N1IA