[Heath] Marauder relay problem

[Wilson Lamb]

Measure relay voltage on coil.
 A quick look at the schematic seems to show that  R67 pulls the cathode UP to cut the tube off when not pulling in, but there's some stuff I can't read. 
 I'd try raising R67, to let more of the tube current go through the coil.  Maybe take it up to 50K.  I don't know if the 220? V indicated for the plate is with the relay pulled in or not.  If pulled in, then the B+ line voltage that feeds V9 minus 220 is the voltage that the coil should see.  See if there are spec's for the coil in the parts list.  Of course, if that B+ is low, it could cause the problem.

To get 14V across the cath resistors looks like about 50mA.

If there's 300V across R67, the current through them is about 8mA and they dissipate about 2.4W...might well be warm.

I'd have used a dropping res in the coil circuit.
 WL

----- Original Message -----
Hi, gang,

I have a problem with the relay shock-mounted behind the meter. This
evening, it wouldn't latch, wouldn't go into transmit. I could hear it
trying to on PTT, a faint clicking. First, I subbed out the 6EA8 V9, no
change. So, I shut down and decided to dismount the relay and move it away
from the chassis to have a better look at it.

It latches partially and with the very lightest touch to the relay's tongue,
latches completely. I just barely touch it, and it latches all the way.
Holds tight when latched and releases completely, no problem there. I'm
thinking that there may be something mechanically that's binding, but I
can't see where, given all the wires attached to its terminals.

I've replaced R65, 66 and the 75K/2W pair R67a and b already, as one of the
ICOD steps pointed those out as components which create a resistive divider
to engage the relay via V9B the relay amplifier. I note that R67 runs really
hot to the touch and that's a pair of 2 watters in parallel. Lot of current
there and I'm wondering if that's normal.

The relay might be going out, but I don't know if that's really the case or
not.

Anyone have a suggestion about this?

73,

Sandy AC1Y

Alexander N. (Sandy) Gerli
'Corgi Cottage'
548 Allred Mill Road
Mount Airy, NC 27030-2202
919-625-7181

A Scotsmen walks about 900 miles each year
Scotsmen drink about 40 gallons of whisky each year
Scotsmen get about 25 miles per gallon


_______________________________________________
Heath mailing list
Heath at puck.nether.net
https://puck.nether.net/mailman/listinfo/heath