[MRCA] [ART-13_Transmitters] Working on my ART-13's

[J. Forster]

Pull the HT brushes on the dyno and bring the HT up to spec slowly with an
external, current limited, DC supply. If the caps then fail, you will not
have collaeral damage.

-John

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> Throughout the last 20 years or so I managed to acquire several ART-13's,
> including an R-807, the Russian copy of it. So far I never had one of them
> on the air, so this is a new experience for me. The ART-13's are of
> several
> versions, a couple of A's, one plain -13 with the TCZ slide, a B and a
> heavily modified one which will be too hard to restore to original
> (connectors were changed and circuit changes galore) so it'll be a parts
> source, and an additional  carcass for parts. I decided it's time to get
> them on the air on the air. I have a Ballantine DY-17/ART-13A dynamotor,
> as
> well as a DY-17A. Unfortunately, the -17A is under a pile of heavy stuff
> right now, so I started out with the old, beat-up -17. I did the usual
> bearing cleaning and relube, and turned it on. Overload and groan. I found
> the 400 V and 750 V brush filter caps shorted. Replaced them and it came
> to
> life. Hooked up the power cable to the first ART-13A "patient" to start
> the
> triage. Autotune turning easily, MO is heard on monitoring receiver, no
> grid/plate current. I found that the 813/811's filaments were not on.
> Filaments checked OK with ohmmeter. Plugging them back in, still nothing.
> They didn't come on until some DeoxIt treatment of the tube socket
> contacts.
> On again, tubes lit up. No grid/plate current. No side tone, but good MO
> signal. Set aside for further troubleshooting later, hooked up ART-13A  #
> 2.
> Side tone OK, MO nice and stable,  but same darn thing as ART-13A #1  with
> the 813/811/s filaments, until the DeoxIt treatment. When the 3 bottles
> finally lit up, this one produced screen and plate current, and power
> output. Just as I was tweaking the loading, something started to smell
> funny. The dynamotor became a smoke generator, as the power died. Post
> mortem of the dynamotor: the 2 RF hash filter chokes on the 400 V and 750
> V
> are toast (National 300 type 1 mH,  3 section pi-wound). Quick metering
> shows the 3 section bathtub cap which are the bypass for the deceased
> chokes, are shorted to ground.
>
> Further smoke tests suspended until I acquire replacement chokes and
> replace
> the bypass caps. Now I have to dig out the almost new-looking DY-17A from
> under the pile of junk in the garage, before I can blow up more things.
>
> I hate the thought that I may be forced to build an AC power supply for
> the
> ART-13, because I like to run military gear the way the original system is
> set up. I don't mind the whir/whine of a well-lubed dynamotor  :-) .
>
>
>
> 73, Meir WF2U
>
> Landrum, SC
>
>
>
>