To ground the grids. Wire or flat strap? I've seen both. What do you guys say?
|
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@...
toggle quoted message
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
|
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
toggle quoted message
Show quoted text
*** 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?
toggle quoted message
Show quoted text
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 ¦¸ ohm Metal Film Fixed Resistor 0.01 ¡À1%
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
?
|
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
|
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 ¦¸ ohm Metal Film Fixed Resistor 0.01 ¡À1%
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
?
|
Re: Early 4 Line supplies
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
?
|
Re: Early 4 Line supplies
I just found a baggie of 1N5408's.
They seem way over-rated - am I missing something, or are they
fine to use?
I also have a bunch of 1N4004's but they seem under-rated.
WDYT?
Thanks,
David KD4E
On 1/27/25 18:55, Gary WB6OGD via
groups.io wrote:
toggle quoted message
Show quoted text
Diodes were new fangled expensive things back in AC-3 days.?
Now they are much better and very cheap.
I think I used all 1n4007s in mine (1KV, 1Amp).? Drake had to
use two types to keep the cost down back then.
73,
Gary
WB6OGD
|
Re: TR-4C Problems with 28.0 and 28.5 bands
And you can elect to have a digest, which basically sends you one or two emails per day.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Monday, January 27th, 2025 at 6:30 PM, Gary WB6OGD via groups.io <winbladgary@...> wrote:
Rich,
Log into the groups.io group.
Over on the left find the "Subscription" link.? Click and the first section lets you change to anything down to
NO emails, so you just go to groups.io and read only the ones you want, when you want.
73,
Gary
WB6OGD
|
I wouldn't trust any caps with paper or cardboard envelopes.? The last ones were probably made in the 1960s.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Monday, January 27th, 2025 at 5:08 PM, John K5MO via groups.io <johnk5mo@...> wrote:
I got some of those yellow paper covered electrolytic at the "drake going out of business sale". I should see if they're leaky or not.
John
On Mon, Jan 27, 2025 at 5:06?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yep and the interesting thing is that the earlier TR-4 can cap doesn't fail like the newer one.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Monday, January 27th, 2025 at 3:53 PM, DavidC KD4E via <qrv= [email protected]> wrote:
Talk about tunnel-vision!
He said TR-4 and it never even occurred to me to even look
closely
at the faceplate.
We were standing in a non climate-controlled space while talking,
and it was cold.
'And that's my story, and I'm sticking to it ..."
Now, I have to learn what the difference is between the TR-4 and
the TR-4C.
Thanks!
On 1/27/25 14:43, Steve Wedge, W1ES/4
via wrote:
Exactly,
which means that any kid or critter could touch dangerous
voltages.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Monday, January 27th, 2025 at
12:32 PM, VE7PS via <ve7ps@...>
wrote:
And the AC-3 did not have a top cover
like the AC-4.
PS
On Mon, Jan 27, 2025 at
9:28?AM Steve Wedge, W1ES/4 via <w1es= [email protected]>
wrote:
The
circuit board for the rebuild kit mounts on top of the
chassis. You can also do a 1 for 1 replacement of the
capacitors with cans, which is more expensive but
preserves the original layout. If you put the new caps
underneath, you can leave the originals, unconnected, on
top. It is more difficult to mount caps underneath but
it is certainly doable and I had done several that way.
What you save on the new board, you more than make up
with time spent. Everyone's equation of time vs cost is
different...
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a
banana.
Sent with secure email.
On Monday, January 27th, 2025 at 12:22 PM, DavidC
KD4E via <qrv= [email protected]>
wrote:
I don't understand the 'cage' thing.
There a solid metal plate over the bottom of this
PS.
Thanks
On 1/27/25 11:52, Evan via wrote:
As a side note, some prefer the
AC-3 over the AC-4 due to the "open air" sort of
cooling while the AC-4 has a small number of
"hot air exhaust slots". I have no personal
experience with the AC-3 so I am not aware of
reliability versus the AC-4.
On Monday, January 27, 2025 at 11:47:12
AM EST, Steve Wedge, W1ES/4 via <w1es@...>
wrote:
I would simply go ahead and re-cap
this supply. Paper bodied electrolytic
capacitors are prone to dry out.
If you want to wait, replace just
the bias supply¡¯s capacitor, as if you
lose your bias supply, your finals, at
best, will be stressed beyond their
ratings, shortening the life of the
tubes.
The rebuild kit for the AC-3 costs
more than the one for the AC-4 because
it needs a ¡°cage¡± over the board to
prevent contact with dangerous
voltages. It is well worth it, though.
Steve Wedge, W1ES
Time flies like an arrow. Fruit
flies like a banana.
On Mon, Jan 27, 2025 at 10:54, DavidC
KD4E via
< qrv@...>
wrote:
I accepted a
trade offer of a TR-4 for my
troublesome TR-3.
Opened things up and have a few
questions for those in the know ...
Images here:
The power supply has some sort of
filmy deposit on top - I'm thinking
it's residue from tobacco.
1. I'm real shy about putting moisture
on the tops of the paper
electrolytics
but would WD-40 or a citrus-based
cleaner using a q-tip be safest for
the
chassis?
2. Do the caps appear to be original?
(The rig works but I'd rather update
things, if the caps are ancient, prior
to setting it up on my operating
desk.)
3. Does the serial number reveal
anything useful, please?
Thanks,
David KD4E
|
Re: Early 4 Line supplies
David,
Ha ha.. I am 4 years older.
Us old guys like to get the radios we couldn't afford back in the day.
I sold my TR-4C (flipper) to a guy in the bay area.? He went to UC Berkeley, the TR-4C was their club radio,
he remembered it so fondly he wanted to experience it again even though he had an IC-7300!
73,
Gary
WB6OGD
BSEE UC Davis '73
?
?
|
Craig W8CS
Scott N1IA
Jim Shorney
DavidC KD4E
Gary WB6OGD