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

[jcoward5452 at aol.com]

I concur. And I am also afeared of fireing up the "screaming memeies" 800 cy inverters I have for the GO-9's! The fire cheif lives right next door!
 When I as a kid I experimented with a Dynajet pulse jet engine.When I fired that up the whole volunteer fire dept. showed up!Close enough in fequency to the town alarm.
 Jay KE6PPF



-----Original Message-----
From: Ray Fantini <RAFANTINI at salisbury.edu>
To: Meir WF2U <wf2u at ws19ops.com>; 'MRCA' <mrca at mailman.qth.net>; milsurplus <milsurplus at mailman.qth.net>
Sent: Wed, Feb 15, 2012 5:29 pm
Subject: Re: [Milsurplus] [MRCA] [ART-13_Transmitters] Working on my ART-13's


You sir are the king of the Motor Generator, the world of the carbon brush, 
rmature and re- pack able bearing. Perhaps because I was scared at a young age 
ack in the seventies of having to learn what I thought was at the time 
ompletely useless information on the maintenance and operation of dynamotors to 
ake the old second class radio telephone test I have always had a grudge 
gainst them and wet cells too. Looking at the responses that have been posted 
t appears that the cult of all original or not at all is in no danger. I am so 
nspired that I may revisit a abandon project to activate a 115 volt 400 cycle 
hree phase rotary inverter that I have its just that initial testing once I was 
ble to develop enough current surge to get the thing to fire up and run up to 
peed it sounded like it was going to take off and fly around the room.
________________________________________
rom: milsurplus-bounces at mailman.qth.net [milsurplus-bounces at mailman.qth.net] On 
ehalf Of Meir WF2U [wf2u at ws19ops.com]
ent: Wednesday, February 15, 2012 7:26 PM
o: art-13_transmitters at yahoogroups.com; 'MRCA'; milsurplus at mailman.qth.net
ubject: Re: [Milsurplus] [MRCA] [ART-13_Transmitters] Working on my ART-13's
Thanks to all who gave their opinions and ideas.
First of all, I realize now that testing the ART-13 could be done easier and
afer with an AC supply. This eliminates the dynamotor as the second
otential source of problems in the system so it's easier to troubleshoot
ne assembly at a time.
 skipped the AC power supply route from two reasons: I didn't think the
ynamotor will have a problem - I'm using my ATD, ARB, ARC-2, several
C-348's and Wireless Set 19 with their original dynamotors. Although I have
he original TCS AC supply, I also use the dynamotor supply with it
ccasionally. None of the dynamotor supplies had any failures (should I add
o far?).
ncidentally, the oldest dynamotor is that of the ATD (1940)which I got NOS
-4 years ago - incidentally the voltages are similar to those of the
TC/ART-13 but lighter current, so the dyno is a somewhat smaller and
ighter than the DY-17.
he way I used to turn on a dynamotor for the first time is by removing the
V brushes, I let it spin free just on the input voltage and monitor for
eat, and/or uneven running while watching the input current. I let it run
or about one hour. I have a surplus, non-current limited 24-28 V selectable
utput at 50 A (or 12 VDC nominal at 100 A depending on the output
trapping).
eeding a voltage equivalent to the output voltage to the dynamotor unit
ithout the brushes is a good idea and next time I'll definitely utilize my
djustable HV lab supplies to do that.
he other reason for skipping testing the ART-13's with an AC supply is that
lthough I acquired a very nice homebrew supply together with the heavily
odified ART-13 I mentioned in my previous posting, I modified it to power
p my Canadian Marconi CM-11 transmitter (late WW2 ex- Royal Canadian Navy),
hich requires 400 VDC for the low voltage (master oscillator,
ultipliers/driver) and 1000-1200 VDC for the 813 output. This is a 100 W
utput (on CW) transmitter, with screen modulation for AM. I removed the 15
 24 VDC supply from it and replaced it with a 1 A 24 V supply - this
ransmitter only needs 24 VDC for the relays, the filaments are supplied by
n internal filament transformer with 115 VAC 60Hz primary. The control
ircuitry with the relays is different from that required by the ART-13, and
he negative sides of both high voltages are grounded. The metering is done
n the transmitter with internal sensing resistors.
o, I'll have to build an AC supply for the ART-13... There is enough
eference material on that and of course I'm aware of the external metering
esistor, it's placement in the circuit and its value.
or those who have the ART-13 and DY-17 schematics, the failure took out
2702 and 2703 and the 3 section bathtub cap C2702 (rated 600 VDC) measures
hort to the ground on all 3 sections. The 400 V and 750 V brush capacitors
re tubular, oil impregnated units, .12 uF each, rated 600 VDC and 1250 VDC
espectively which shorted (the 400 V one first) after it ran with the
rushes for a few minutes. I replaced them with mylar caps, which fit inside
he frame where the originals were.
73, Meir WF2U
andrum, SC
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