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Okay quick info on progress on the saga...

Replaced V4&V5 with 2 NOS tubes, that brought the meter down from ~5-6 S units to ~4 S units, still the zero pot needs to be maxed/minimize depending how we look at it.

Replaced V3 as well since I got hold of an 12BE6, made no differens.

I totally forgot I had several 12au6's / EF94 in stock, changed V2, just for the fun of it, made no change as expected though.

So, back to the drawing board.

Cheers..

On Sat, Mar 9, 2024 at 9:05?PM Steve Wedge, W1ES/4 via <w1es=[email protected]> wrote:

Crackling sounds that affect the AGC (and thus cause the meter to deflect) are worthy of investigation. You may have a component that is either cracking (resistor) or has some intermittent dialectric issues (capacitor).

I have been promising myself that I would look into creating one of those "Mr. Carlson Super Probes". "Mr. Carlson's Lab" is on YouTube and he created an AC probe that can sniff out problems like internally arcing components. The probe is similar in concept to the old signal tracers but it is much more sensitive. I believe he has two versions: one with through-hole and the other using SMT. He demonstrated the probe on an old receiver that was showing "crackling" noises. and was able to find the bad cap within a few minutes.

Anyway, I scored another victory today: I figured out how to add a 3rd monitor to the shack computer! More screen area -- yay!

73,

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent with secure email.

On Saturday, March 9th, 2024 at 1:14 PM, Michael Jensen <kavigal@...> wrote:

Well sorry for the slow reply, work just tend to take up too much of one's spare time ;).

Sounds like a very nice trip you and XYL is planning, now I do not travel much these days(I used to), now I just mainly work from home and enjoy monitoring the HF bands, when 'Teams' decides to leave me alone ;).

About that Beer.. Guess I already owe you one, at least as an excuse to get myself one.

Been a few years since I was in Copenhagen, I live in the opposite end of the country all the way up to the North about 50KM south of the most northern point..

And yes we will get to the bottom of this issue, actually I notice something, when I turn on the radio 'ON' to "standby" position the meters consequential "jumps" from ~S9+20 to the S9+40 meter mark, first time I noticed I just though "ohh meter is sticky" but then while troubleshooting I fiddled with the RF gain and guess what?

No "sticky" meter when RF gain is fully cranked up quickly.

I noticed twice when "cold" starting the rig, and coinciding "crackling" sound when the meter "jumped", not sure what the right term is in English / U.S.A'ish but same sound a hot 6146B tube can produce just not so pronounced.

It may not be related, just noticed it.. So.. status quo, really eager to get that 12be6 swapped, but the mail man is apparently on vacation in Hawaii current time.

/Michael.

On Thu, Mar 7, 2024 at 6:48?PM Steve Wedge, W1ES/4 via <w1es=[email protected]> wrote:

Yeah, that's a shame that we still have such impediments. In the grand scheme of things, a few 60 year old tubes are nothing. If I was going to Demark this year, I'd pop a couple in my bag and trade them for a beer but we will not be in the area. We will be in HB9, DL, OE, OK, F, G, GW, GM and TF this summer. My XYL is not a ham, so I'm not bringing any radios, unfortunately :-) I mention this in case you're in any of these areas in June or July.

In a couple years, perhaps, we will get to Scandinavia. I worked in Copenhagen for a week long ago and have wanted to tour that area.

We will get to the bottom of this.

73,

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent with secure email.

On Thursday, March 7th, 2024 at 12:26 PM, Michael Jensen <kavigal@...> wrote:

Steve, I'd love the approach of shotgunning, but nope I do not have a complete set.

I do have 2x12ba6 in the mail and 1 12be6 also in the mail, so that will be the starting point.

I did consider and I'd love to get a complete set from K5SVC, but it would add more than 4 times
the money I have in the R4B already, getting tubes from the US to Europe is .. insane..
So thank you to the Danish Government ;)

Anyways, will try the three tube change first, that's kinda where I'm at now.

/Michael

On Thu, Mar 7, 2024 at 5:33?PM Steve Wedge, W1ES/4 via <w1es=[email protected]> wrote:

Now is the time, if you either have a spare set or have another R-4B, to swap every tube out at the same time (“shotgunning”).

I had an R-4B that was vexing me to no end until I replaced all the tubes and then put swapped the old ones back, one at a time. I found two bad/gassy 12BA6’s and a 12BE6 that passed the tube tester but was no good.

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent from for iOS

On Thu, Mar 7, 2024 at 09:29, Michael Jensen <kavigal@...> wrote:

When unpowered, S1+a hair, so very close to zero.

Have checked the following resistors so fare...

Just FYI, nothing more..

R9 1.5K** Board 9 OK
R8 220K** Chassis Right Side -R OK
R12 1.5k**Board 9 OK
R13 1.5K**Board 9 OK
R16 1.5K**Board 7 OK
R17 12K* OK
R24 18K* OK

R136 1k** Chassis Left Side -R OK
R142 4.7K**Board 3 OK
R146 22K** Board 3 -- coil OK

/Michael.

On Thu, Mar 7, 2024 at 3:19?PM Steve Wedge, W1ES/4 via <w1es=[email protected]> wrote:

Yes, I have been bit by one of the meter terminals. It hurts :-). This circuit is at around 150V potential.

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent from for iOS

On Thu, Mar 7, 2024 at 01:23, Glenn, OZ1HFT <glenn.mh.dk@...> wrote:

Hi Michael

More safety: Let the Drake unlugged power plug and cable be visible to you, on your workbench, while you work on the Drake.

(Then it be much harder to get an accidently electric shock.)

--
best regards,

Glenn, OZ1HFT