[Milsurplus] Working on my ART-13's

Tue Feb 14 13:24:32 EST 2012

Just finally got my shipment and will be digging out the R-807 and getting it up and running.  I also have the dyno supply , but I think I will use an AC supply to check everything out.  Mine is newer than the ART-13s being built in the 70s.  Will pair it with my US-9 and see how it goes.  Hope to get it all done by the end of the summer.  hate it when work gets in the way.

John  WD5ENU

From: Ray Fantini <RAFANTINI at salisbury.edu>
To: Meir WF2U <wf2u at ws19ops.com>; "milsurplus at mailman.qth.net" <milsurplus at mailman.qth.net>; 'MRCA' <mrca at mailman.qth.net> 
Sent: Tuesday, February 14, 2012 12:11 PM
Subject: Re: [Milsurplus] Working on my ART-13's

I have done a couple ART transmitters and never used the dynamotors. With an all new component radio without fifty years of storage under questionable condition starting and testing a transmitter is no issue but what's the point of using a motor generator with bearings, brushes and other components that cannot be replaced while in the trouble shooting stages of a project? Do yourself a favor and build the AC supply, after you get the radio working correctly then go ahead and install the correct dyno supply for the authentic feel. What happens if you're ART shorts the modulation transformer or develops a HV or B+ short and damages your dynos windings? Or burns up the shunt resistor on the dyno deck. None of that's an easy fix. Things tend to go wrong in the first couple minutes of operation or at least that's what I have found so once the radio is working well on the external modern supply then go for accuracy. I have no idea myself being that radio was
 so far before my time b
ut would assume in the old avionics shops they had a AC power supply for when they worked on them just to avoid the noise and current requirements . I know the one and only bench mock up I have ever seen for the ARC-38 had an external 120 volt 60 cycle power supply that not only replaced the dyno but provided the 115/400 cycle too. Just because you want everything 100% accurate does that mean you have to use period tools and technique? The external power supply doesn't have to be nice being it's only a means to an end. Think I have run anything around 400 for the B+ and 900 to 1,200 for the HV and the transmitter worked good, may not have been full power but once you get it stable and working then hit it with the correct dyno supply. At least that's what I would do, but that's just me.
RF

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Meir WF2U
Sent: Tuesday, February 14, 2012 12:12 PM
To: ART-13_Transmitters at yahoogroups.com; milsurplus at mailman.qth.net; 'MRCA'
Subject: [Milsurplus] Working on my ART-13's

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, M
O 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 

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