In the 50s I used to make the tuning knob shaft with a piece of car
radio antenna that fit and filled it palster of paris and pushed it and
let it harden. It's removeable but I'll bet there are some better
synthetics available today. I see the splines selling for $5 top $10 on
ePay.

--

73
Hank WD5JFR
"cliff wright" wrote in message
...
Dave wrote:
Rewire the filaments from 24 volt configuration to 12 volts.

You need +250 for plate voltage.

It's been 50+ years since I modified one, so I don't know the pin
assignments.

/s/ DD



genev wrote:

I just got an ARC 5 receiver and wonder if anyone has any tips on
modifying it; I had one in the 1960's, but can't remember what I had
to do to it. I think I replaced the dynamoter plug with a modern
one, but dont remember how I put the tuning knob on the front.
Also, what voltages are needed?
Thanks in advance for any info.
Richard
K1TAV



Hi!
The tuning needs a special socket in a splined multi pointed star
formation.
The best source is of course the original remote cables, but finding
those would be a minor miracle by now. It just might be possible, if
you have well stocked hardware store near you to find a nearly
identical socket which could be made to fit. Don't forget the output
impeadance of the audio transformer is about 200 ohms to match the
original crew headsets. Actually by now I reckon that you might find
that a lot of the bypass and coupling caps in the cans along either
side of the chassis are leaky and may need replacing.
I'm not sure which RX you have, there are actually about 5 or 6
versions. The Hf ones above 3 MHz or so are very lacking in
selectivity
with an IF frequency of 1.4 or 2.6 (I think) MHz.
I still have one of my first homebrew Ham RX's that I made back in the
1960's when I first came out to NZ.
It was a triple superhet, Ist IF tunable from 3.5-4MHz, 2nd IF 2xARC5
IFT's at 1.4MHZ and 3rd IF 2 stages of 85KHz using "Q5er" ARC5
transformers with 6 tuned circuits.
Worked very well but did have some image problems 2.8 MHz away from
the wanted signal.
Hope you can get it all going OK. I sem to remember several ideas
published back in the 1960's and 50's which you might be able to trace
on the web.
73's
Cliff Wright ZL1BDA ex G3NIA.