[ARC5] Operation of ARC-5 Transmitter

[Cliff Miller]

I have seen the green glow.  Turned out I had two problems.  The advice to
take C58 out of the circuit was solid - it was pulling the Oscillator
voltage down.  Rookie mistake!  Lots of advice out there to change the
bathtub first.  I removed all three leads.

Then I found another problem - K53 stopped picking up.  I'd missed that
because the other relay noise. Also, I think it was working at first.
Yesterday, I read reduced voltages on pins 3 and 4 of the eye tube - 150
volts or so, so the relay had to be working.

I bypassed K53 and with the bathtub disconnected, the green appeared.  Pins
3 and 4 of the eye tube now read 200V and more.  Adjusting the frequency
brought the shadow as expected.

K53 has the filament voltage on one side of the coil and the key line on
the other.  The coil does not read open.  More troubleshooting there.

Thanks everyone again for your help.

On Sun, May 15, 2016 at 3:38 PM, <WA5CAB at cs.com> wrote:

> Did you jumper the correct contact on K53?
>
> Robert Downs - Houston
> wa5cab dot com (Web Store)
> MVPA 9480
>
> In a message dated 05/15/2016 07:41:33 AM Central Daylight Time,
> cliff52 at gmail.com writes:
>
> Thanks everyone for the replies.  I checked for the screen grid mods but
> found the transmitter to be stock with no SG connections except the rear
> connector.  I had 239V on the oscillator power input and got no glow on the
> 1629.  All the filaments are lit FB but no joy.  Any checks I could do
> before ordering a new magic eye tube?  Is the difference with 250V enough
> to prevent proper operation?
> Again, thanks everyone.
>
>
>
>
>
>


-- 
Cliff Miller
cliff52 at gmail.com
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