Re: Drake R4C myseriously dead
If, as others have suggested, the Mute jumper is in place on the rear, and the noise blanker (or the jumper) is installed, and the tubes are removed and reseated, and it's still dead, I would use another receiver, tuned to the R4C IF frequencies, to see if
you can trace the signal and find out where it seems to fail.? Then you would know where to focus your attention.? Easiest to do this if the R4C is tuned to a known strong signal.? (Be careful, of course, not to touch the antenna input of the other receiver
to any DC voltage within the R4C.)
-- Art Delibert, KB3FJO
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Hello:
I have a Drake R4C that went through the WB4HFN full service option about 5 years ago. It hasn't been hardly used at all.
Now when I powered it up on a variac, I get power but no signals, no audio, no nothing.
I find it hard to believe that this happened just by sitting. It was covered with a dust cover the entire time in a temp-controlled room.
Is there something I can try? I tried FUNCTION ON, and every setting imaginable. All tubes are lit (but not tested recently).
I plugged in the long gray cord on the MS4/AS4 combo but got no sound. Neither did I get sound from the front headphones.
Ideas?
Thanks
Scott N1IA
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Re: Comments/experiences sought
jerry-KF6VB writes: There's some really neat little stuff out there now. Right here, I have
a project. It's a signal generator I bought from "AF&CH" in Ukraine on=20
Ebay. Jerry, can you post a link to that? I tried a few different searches but nothing showed up. --lyndon
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Re: Drake R4C myseriously dead
Does the S meter indicate anything? You need a signal source. The internal calibrator will do but the MUTE connector needs to be shorted for it to work.
The usual advice to clean the switches applies. Switch contacts can oxidize just from non-use.
I am much more familiar with the B than the C but think that checking pin voltages might provide a clue.
There are other general suggestions if you can't find anything definite, clean all connectors, tube base pins, etc. Some circuits go to ground through screws, work the screws back and forth a little to make sure they are making contact with the chassis, this will sometimes fix all sots of obscure problem. If you have to signal trace a scope will be of great value.
Also, lift the front panel maybe an inch and drop it, any reaction?
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On 1/28/2025 12:59 PM, Scott N1IA via groups.io wrote: Hello:
I have a Drake R4C that went through the WB4HFN full service option about 5 years ago. It hasn't been hardly used at all.
Now when I powered it up on a variac, I get power but no signals, no audio, no nothing.
I find it hard to believe that this happened just by sitting. It was covered with a dust cover the entire time in a temp-controlled room.
Is there something I can try? I tried FUNCTION ON, and every setting imaginable. All tubes are lit (but not tested recently).
I plugged in the long gray cord on the MS4/AS4 combo but got no sound. Neither did I get sound from the front headphones.
Ideas?
Thanks
Scott N1IA
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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Re: Drake R4C myseriously dead
Oh, if someone pulled the Noise Blanker it will not work.
? ? ?Frank Krozel ? ? ? ? ? ?KG9H Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
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On Jan 28, 2025, at 4:06?PM, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
Are all the jumpers installed?
? ? ?Frank Krozel ? ? ? ? ? ?KG9H Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
On Jan 28, 2025, at 4:05?PM, Craig W8CS via groups.io <craig_severson@...> wrote:
I would go for the simple stuff first.?
?
Make sure that none of the tubes are loose. Grab each one and re-seat it with a circular motion to make sure that it's centered and no pins are oxidized.?
?
Past that, it's time to check power supply voltages.?
--
Craig/W8CS
Greenville, SC
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Re: Grounding the grids, L7
Flat brass stock has lower inductance than wire. ?But remember that the grids were originally grounded via an RF choke with thin wire.
To ground the grids. Wire or flat strap? I've seen both. What do you guys say?
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To ground the grids. Wire or flat strap? I've seen both. What do you guys say?
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Re: Drake R4C myseriously dead
Isn't there a shorting circuit via an RCA jack on the back panel that has to be considered?
Hello:
I have a Drake R4C that went through the WB4HFN full service option about 5 years ago. It hasn't been hardly used at all.
Now when I powered it up on a variac, I get power but no signals, no audio, no nothing.
I find it hard to believe that this happened just by sitting. It was covered with a dust cover the entire time in a temp-controlled room.
Is there something I can try? I tried FUNCTION ON, and every setting imaginable. All tubes are lit (but not tested recently).
I plugged in the long gray cord on the MS4/AS4 combo but got no sound. Neither did I get sound from the front headphones.
Ideas?
Thanks
Scott N1IA
|
Re: Drake R4C myseriously dead
Are all the jumpers installed?
? ? ?Frank Krozel ? ? ? ? ? ?KG9H Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
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Show quoted text
On Jan 28, 2025, at 4:05?PM, Craig W8CS via groups.io <craig_severson@...> wrote:
I would go for the simple stuff first.?
?
Make sure that none of the tubes are loose. Grab each one and re-seat it with a circular motion to make sure that it's centered and no pins are oxidized.?
?
Past that, it's time to check power supply voltages.?
--
Craig/W8CS
Greenville, SC
|
Re: Drake R4C myseriously dead
I would go for the simple stuff first.?
?
Make sure that none of the tubes are loose. Grab each one and re-seat it with a circular motion to make sure that it's centered and no pins are oxidized.?
?
Past that, it's time to check power supply voltages.?
--
Craig/W8CS
Greenville, SC
|
Drake R4C myseriously dead
Hello:
I have a Drake R4C that went through the WB4HFN full service option about 5 years ago. It hasn't been hardly used at all.
Now when I powered it up on a variac, I get power but no signals, no audio, no nothing.
I find it hard to believe that this happened just by sitting. It was covered with a dust cover the entire time in a temp-controlled room.
Is there something I can try? I tried FUNCTION ON, and every setting imaginable. All tubes are lit (but not tested recently).
I plugged in the long gray cord on the MS4/AS4 combo but got no sound. Neither did I get sound from the front headphones.
Ideas?
Thanks
Scott N1IA
|
Re: Comments/experiences sought
Of course, it does have a few things parked on top of it.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Mon, Jan 27, 2025 at 23:14, Gordon, KJ6IKT via groups.io < gfsmith@...> wrote:
I feel your pain Steve. My signal generator is a GenRad 1001-A. 50 lbs of pure electrical engineering.
?
73, Gordon KJ6IKT
?
On Mon, Jan 27, 2025 at 02:00 PM, Steve Wedge, W1ES/4 wrote:
Man, you guys should see my R&S SMPD. 50 lbs of 500 kHz to 2.7 GHz German-spec signal generator! Yeah it takes up 1/3 of my bench. That's the downside...
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with Proton Mail secure email.
On Monday, January 27th, 2025 at 3:27 PM, jerry-KF6VB <jerry@...> wrote:
On 2025-01-27 07:07, NU2W via groups.io wrote:
I will stick with the old way---big heavy sig gens, oscilloscope,
muti-meters....
*** Alas I cannot. Limited bench/storage space and bad back. Back in
my salad days, I put in a few years fixing and maintaining big old heavy
test equipment, so there's a bit of nostalgia about that...
There's some really neat little stuff out there now. Right here, I have
a project. It's a signal generator I bought from "AF&CH" in Ukraine on
Ebay. It's
based on an AD9910 Direct Digital Synthesis chip. It generates nice
sine waves using a 900MHz sample clock.
It can also be goosed up to 1.5gHz, but they recommend fan cooling if
you do that.
For HF frequencies, 900MHz is plenty. Spurious are 50dB down. It has a
built in
attenuator - 1 dB steps from 0dBm down to -72dBm.
It wasn't cheap; I bought it fully assembled, with an OCXO ( Oven
Compensated Crystal Oscillator ).
It's got an Arduino card bolted to it; I plan to program that to
implement a signal generator
with a big tuning knob.
- Jerry, KF6VB
?
?
|
Re: Comments/experiences sought
I feel your pain Steve. My signal generator is a GenRad 1001-A. 50 lbs of pure electrical engineering.
?
73, Gordon KJ6IKT
?
On Mon, Jan 27, 2025 at 02:00 PM, Steve Wedge, W1ES/4 wrote:
Man, you guys should see my R&S SMPD. 50 lbs of 500 kHz to 2.7 GHz German-spec signal generator! Yeah it takes up 1/3 of my bench. That's the downside...
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with Proton Mail secure email.
On Monday, January 27th, 2025 at 3:27 PM, jerry-KF6VB <jerry@...> wrote:
On 2025-01-27 07:07, NU2W via groups.io wrote:
I will stick with the old way---big heavy sig gens, oscilloscope,
muti-meters....
*** Alas I cannot. Limited bench/storage space and bad back. Back in
my salad days, I put in a few years fixing and maintaining big old heavy
test equipment, so there's a bit of nostalgia about that...
There's some really neat little stuff out there now. Right here, I have
a project. It's a signal generator I bought from "AF&CH" in Ukraine on
Ebay. It's
based on an AD9910 Direct Digital Synthesis chip. It generates nice
sine waves using a 900MHz sample clock.
It can also be goosed up to 1.5gHz, but they recommend fan cooling if
you do that.
For HF frequencies, 900MHz is plenty. Spurious are 50dB down. It has a
built in
attenuator - 1 dB steps from 0dBm down to -72dBm.
It wasn't cheap; I bought it fully assembled, with an OCXO ( Oven
Compensated Crystal Oscillator ).
It's got an Arduino card bolted to it; I plan to program that to
implement a signal generator
with a big tuning knob.
- Jerry, KF6VB
?
?
|
Re: Early 4 Line supplies
I totally agree with Gary. Do not buy parts from Amazon. Mouser is my preferred vendor, with DigiKey as #2. On Mon, 27 Jan 2025 18:08:02 -0800 "jerry-KF6VB via groups.io" <jerry@...> wrote: On 2025-01-27 17:40, Gary WB6OGD via groups.io wrote:
David,
Diodes are so much better than they used to be.
Now, buying from Amazon.. I think is pretty much the same as ebay..
Those parts may be good, or they may
be re-labled questionable parts. YMMV. *** I've had reasonably good luck at Amazon. Except for this one box
of 3-terminal regulators with lots of dead ones, and ones that were
grossly out of spec. -- 73 -Jim NU0C
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Re: Early 4 Line supplies
If you're not in a hurry, Digikey has a longstanding (unpublicized) policy that if
you send a check the shipping is free.
I took advantage of that, recently, to get a 115v-115v 50va isolation transformer.
David, KD4E
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*** For medium/large orders that's true.? What kills you with Mouser & Digikey is
the shipping.? I've ordered a fifty-cent part and paid $8 shipping.
? One vagary of Amazon is that they make you buy "kits" with lots of parts.? I needed
one 50MHz crystal.? For the price of that crystal+shipping( at Mouser ) I got a box with
50 or 100 (forget which ) crystals.? Amazon builds my junkbox!
??????????????? - Jerry, KF6VB
|
Re: Early 4 Line supplies
On 2025-01-27 17:40, Gary WB6OGD via groups.io wrote: David,
Diodes are so much better than they used to be.
Now, buying from Amazon.. I think is pretty much the same as ebay..
Those parts may be good, or they may
be re-labled questionable parts. YMMV. *** I've had reasonably good luck at Amazon. Except for this one box of 3-terminal regulators with lots of dead ones, and ones that were grossly out of spec. But luck is what it is. Amazon doesn't seem to enforce any sort of standards. I squawked the bad regulators and they deleted my review. I think if you go to a real supplier, the price won't be that much
higher and you can be sure they are good parts. *** For medium/large orders that's true. What kills you with Mouser & Digikey is the shipping. I've ordered a fifty-cent part and paid $8 shipping. One vagary of Amazon is that they make you buy "kits" with lots of parts. I needed one 50MHz crystal. For the price of that crystal+shipping( at Mouser ) I got a box with 50 or 100 (forget which ) crystals. Amazon builds my junkbox! - Jerry, KF6VB
|
Re: Early 4 Line supplies
? ? ?I just wanted to make a comment here. David spent a bit of time making sure he was ordering the right parts. I think “wasting money “ with the kits is a bit harsh. That extra money amounts to paying someone to source and confirm the various components which is not second nature like it is to us old far…er…folks. I’m really glad to see younger folks with a desire to learn which end of the soldering iron to pick up.? ? ? ? By the way, I was in the 7th grade when I first picked up a soldering iron. :-) ?Got my call in ‘54. Where the heck does the time go. Oh wait, that’s what old people say. ;-)?
Tony - W9JXN?
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On Jan 27, 2025, at 7:28?PM, DavidC KD4E via groups.io <qrv@...> wrote:
?
Cool. (I didn't want to miss something about other
characteristics of the diodes).
I think I found what I need on amazon:
Chanzon 50pcs 1W 150K Ω ohm Metal Film Fixed Resistor 0.01 ±1%
Tolerance
?? ?
Tsnamay 100 Watt 100 Ohm Resistor Aluminum Case Wirewound Chassis
Mounted 2Pcs
10PCS 47uF400V Radial Electrolytic Capacitors Volume 16x25 mm
Generic 4 pcs 150uF 400V 18x35mm Electrolytic Capacitor
0.71x1.38in Aluminum
Cermant 5PCS 400V 100UF Capacitor 18x30MM (0.71x1.18in) High
Frequency Aluminum Electrolytic
Total for all $35.91 and free shipping.
It will leave me with some spare parts for other projects.
Thanks,
David KD4E
On 1/27/25 20:14, Gary WB6OGD via
groups.io wrote:
5408s are 3Amp IIRC.
?
That is fine, you can go up rated but not down.
Same with the voltage and capacitance of the the caps and
wattage rating on the resistors.
?
73,
Gary
WB6OGD
?
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Re: TR7, considering TIP29 as a replacement for EP487
Can your analyzer create a Spice model from the EP487 data? I'm playing around with Spice to see what happens to the DC operating point with different transistors. On Wed, 22 Jan 2025 19:59:31 -0800 "Glenn Hetchler WB0DKT via groups.io" <ghetch@...> wrote: Having purchased a Peak Atlas DCA75 Pro semiconductor analyzer (which I like and will be discussed again in another thread about this brick), and having a couple removed EP487s to compare to the new TIP29s, I set about seeing how similar the two types of transistors were. -- 73 -Jim NU0C
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Re: Early 4 Line supplies
David,
Diodes are so much better than they used to be.
Now, buying from Amazon..? I think is pretty much the same as ebay..? Those parts may be good, or they may
be re-labled questionable parts.? YMMV.
?
I think if you go to a real supplier, the price won't be that much higher and you can be sure they are good parts.
Your labor(!) cost is higher, if you have to replace them later you will wish you go good ones in the first place.
I typically use Mouser.com or Digikey.com.? In caps, I get the longest life, highest temp rated ones, again, price is
not much more.? You will be saving a lot over those pcb kits anyway.
?
I don't think I have found a bad cap or diode in the gear I have restored.?? The old (USA made) caps actually test
better (Ufd, ESR) but I can't test leakage at high voltage.? After changing, I have never noticed a change in the device
operation.? Maybe I have just been lucky.? I do change everything though if I am going to re-sell, buyers want to see
that.
?
73,
Gary
WB6OGD
?
|
Re: TR-4C Problems with 28.0 and 28.5 bands
Stick around, it will taper off after a while. Or set your subscription to web only on groups.io. On Mon, 27 Jan 2025 17:49:02 -0500 "Rich W3RJ via groups.io" <w3rj@...> wrote: It's not that I'm no longer interested in this Drake news and discussion
but I now get way, way too many emails from this group. How do I get
myself off of the mailing list?? Thank you all.
Rich W3RJ -- 73 -Jim NU0C
|
Re: Early 4 Line supplies
Cool. (I didn't want to miss something about other
characteristics of the diodes).
I think I found what I need on amazon:
Chanzon 50pcs 1W 150K Ω ohm Metal Film Fixed Resistor 0.01 ±1%
Tolerance
?? ?
Tsnamay 100 Watt 100 Ohm Resistor Aluminum Case Wirewound Chassis
Mounted 2Pcs
10PCS 47uF400V Radial Electrolytic Capacitors Volume 16x25 mm
Generic 4 pcs 150uF 400V 18x35mm Electrolytic Capacitor
0.71x1.38in Aluminum
Cermant 5PCS 400V 100UF Capacitor 18x30MM (0.71x1.18in) High
Frequency Aluminum Electrolytic
Total for all $35.91 and free shipping.
It will leave me with some spare parts for other projects.
Thanks,
David KD4E
On 1/27/25 20:14, Gary WB6OGD via
groups.io wrote:
toggle quoted message
Show quoted text
5408s are 3Amp IIRC.
?
That is fine, you can go up rated but not down.
Same with the voltage and capacitance of the the caps and
wattage rating on the resistors.
?
73,
Gary
WB6OGD
?
|
Craig W8CS
Scott N1IA
Jim Shorney
DavidC KD4E
Gary WB6OGD