Two comments here.
Rule #1 of vintage radios: Never leave them running unattended, ever for "just a minute". That's all it takes to smoke an unobtanium part if something goes sideways. I'm not assuming you have done this, but just FYI. And check EVERY fuse to make sure it is the correct value. I think all of us here have probably seen gear where someone swapped in an oversize fuse because it was the only thing they had on hand and then forgot about it. That is just tempting fate.
Also, the best tube tester is the circuit that you want it to operate in. Tube testers are great for sorting out tubes that are dead or very gassy but they often miss tubes that are off just far enough not to work in your circuit. This especially applies to final tubes. Your average tube tester can't test a final tube under power at 28 MHz. Also, resist the urge to re-tube the entire radio just because you can. You may find that you have more problems than you started with. Most, if not all, of the original tubes are probably just fine. Best practice is to collect a set of known good spares that you can swap in one at a time if a problem comes up.
73
-Jim
NU0C
On Wed, 10 Jan 2024 17:52:35 -0600
"Ryan NV5E" <ryanjones2150@...> wrote:
You are correct, Steve, I have already put power to it. I¡¯ve ran it a few days, mostly letting it just sit there under power.
I had to box it up today because I had two welding jobs holding, waiting for me to get access to my fab table.
Going to push late tonight and get this done, then see if I can pull it back out and work on it/play with it some more. I know there¡¯s a lot for me to learn and this project will do me good.
A friend of mine, who actually saw this post, has a tube tester, so that¡¯s probably smart. Go ahead and test the little tubes in here and make sure they¡¯re all choochin like they should before I move in to other things.
Ryan
NV5E
On Jan 10, 2024, at 3:49 PM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
?I believe that Ryan has already fired everything up, so no variacs are needed at this point. A view of the top and bottom of the chassis will be helpful. There are few mods done to the earlier Twins. I would check to see if anything needs to be done to the receiver with respect to that LF convertor. I am not familiar with its use and don't know if the receive path is interrupted when it's plugged in.
The cheap variacs are useable but you need to remove the covers and make sure that all of the ground bonds are good and solid. I have one running my station for over a year and it's working fine. I would not fire up all of my rigs at the same time on it. Looking at the gauge of the wire, 10A continuous is probably fine on it.
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent with Proton Mail secure email.
On Wednesday, January 10th, 2024 at 2:04 PM, Lyndon VE7TFX <lyndon@...> wrote:
Ryan NV5E writes:
I don=E2=80=99t know what all else is inside. I pulled the cover off the re=
ceiver the other day, just to take a look around. I like how it=E2=80=99s a=
ll copper in there. And thanks for the heads up on the voltage in there.
Ryan, if you can, pop the covers off the tx and rx and get some
(high resolution and well lit) pictures of the top and bottom
chassis of both, then post those to the list.
Just by eyeballing those somebody might be able to spot if a previous
owner has been golden screwdrivering in there, or if there are any
other gotchas that stand out.
I also second the advice about putting both rigs on a variac to
start. Given their age, a little babying is in order. You can buy
variacs on fleaBay for <$100, and that is money well invested. A
5A should do, although a 10A would give you more head room on the
transmitter. Watch how much current you pull through the variac.
If you run both the rx and tx through it concurrently, you need a
10A.
Do NOT buy one of the cheap chinese bright red ones you see everywhere.
They are death traps. (See the mailing list archives -- somewhere
around last spring? -- for a lively discussion on that topic.)
Note the variac will not carry the power supply for the amp. For
that you might consider just pre-emptively recapping the power
supply. But take a look inside the PSU first, as the former owner
might have done that already.
And finally, as others have said, buy or download the manuals for
everything and (re-)read them until you have them memorized :-)
--lyndon
--
73
-Jim
NU0C
Jim Shorney