Signal Corps Wireless Set No. 19 MK II
 

Chris Suslowicz wrote:
So, I guess my FIRST question is what the meter movement is. I gather
from the schematic that it's an ammeter but I don't know what resistance
or full-scale current.

Offhand, the meter os 0.5 mA FSD, scaled 0-15 and 0-600. I'm not sure what
the internal resistance is supposed to be (all the ones I've just looked
at say "WS19 Voltmeter", which is not exactly helpful[2].

Okay, so I can try a generic 0.5 mA meter out of the junk box and probably
expect it to work. I can do that.

Ah... by "Pye sockets" I assume you mean the power and control ones?

("Pye connector" usually means the antenna connectors, which were used
on all sorts of kit.)

Yes! Also, the "key" connector appears to have more than just key contacts
on it!

Can you get the solder cleaned off the pins, or are you looking for
replacement power and control plugs as well as the sockets? I've got
a few spares but am on the wrong side of the pond so shipping will
take a while...

I can easily clean the solder off the pins; I have an SMT workstation
with the hot air and vacuum stuff. So I just need the sockets.

I don't think I am going to have the time to get this one up and
running for Field Day. This year anyway.

It's good to have a hobby.

So, since I have just the single No. 19 set with none of the accessories,
what is the easiest way to use it? I can take the antenna lead off to a
roller inductor and then to a long-wire antenna, no problem. I can easily
use an existing power supply to drive it, or build one out of junkbox parts
if I can get the connectors. How do I connect a headset, mike, and key up
elegantly without using the outboard box?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Signal Corps Wireless Set No. 19 MK II
 

In article ,
(Scott Dorsey) wrote:

Chris Suslowicz wrote:
So, I guess my FIRST question is what the meter movement is. I gather
from the schematic that it's an ammeter but I don't know what resistance
or full-scale current.

Offhand, the meter os 0.5 mA FSD, scaled 0-15 and 0-600. I'm not sure what
the internal resistance is supposed to be (all the ones I've just looked
at say "WS19 Voltmeter", which is not exactly helpful[2].

Okay, so I can try a generic 0.5 mA meter out of the junk box and probably
expect it to work. I can do that.

Ah... by "Pye sockets" I assume you mean the power and control ones?

("Pye connector" usually means the antenna connectors, which were used
on all sorts of kit.)

Yes! Also, the "key" connector appears to have more than just key
contacts on it!

It incorporates a switch to put the set onto transmit when the plug
is inserted. It takes a standard 2-pole jack plug, but....

_WARNING!_ The key operates on the +250V supply to the buffer stage,
so you need an insulated key, and an insulated (no exposed screws)
jack plug. Otherwise you will get a nasty belt and there will be
a considerable amount of cursing (or worse).

The "official" key is "Key & Plug Assy No.9", and is well insulated.

Can you get the solder cleaned off the pins, or are you looking for
replacement power and control plugs as well as the sockets? I've got
a few spares but am on the wrong side of the pond so shipping will
take a while...

I can easily clean the solder off the pins; I have an SMT workstation
with the hot air and vacuum stuff. So I just need the sockets.

One each, 6 & 12 pin... I can do that. Also a Pye connector (or two)
for the aerial connection.

I don't think I am going to have the time to get this one up and
running for Field Day. This year anyway.

It's good to have a hobby.

So, since I have just the single No. 19 set with none of the accessories,
what is the easiest way to use it? I can take the antenna lead off to a
roller inductor and then to a long-wire antenna, no problem.

Aerial metering is done by a current transformer in the variometer, so
you'll need to add something to replace that: thermocouple ammeter or
a modern ATU with metering.

I can easily use an existing power supply to drive it, or build one
out of junkbox parts if I can get the connectors.

Only 4 of the power connector pins are needed:

+12V DC @ around 4 to 5 amps for valve heaters and relay
+250V @ 120mA HT1 (Range 250 to around 275 volts)
+500V @ 50mA HT2 (Range 490 to 540 volts) (for the 807 PA stage only)

How do I connect a headset, mike, and key up
elegantly without using the outboard box?

The mike and headset connections all come out on the "control" plug,
along with the Tx relay line. Best bet is a short cable to a diecast
box with suitable connectors, unless you've got an original headset
in which case wire a snatch socket straight into the 12-pin socket.

You may also want to pull the "No.10 control unit" trick at the same
time. This converts the intercom amplifier into a microphone preamp,
so you don't need to shout into it.

The set takes a dynamic microphone, and low impedance headphones -
up to about 7 pairs can be used, so anything from about 50 - 300 ohms
should work OK for the headset output, and 300 - 600 ohms for the mike.

The reply-to addrss is valid, let me know your postal addess and I
can send some useful bits off tomorrow morning.

Chris.
--
ONE %RING TO RULE THEM ALL, ONE %RING TO FIND THEM,
THIS LINE INTENTIONALLY LEFT BLANK.
ONE %RING TO BRING THEM ALL, AND IN THE DARKNESS BIND THEM,
IN THE LAND OF ARMONK, WHERE THE SHADOWS LIE.