[ARC5] "Heath" AircraftTransmitter, and now Receiver.

[David Stinson]

----- Original Message ----- 
From: "Robert Nickels" <ranickel at comcast.net>
To: <arc5 at mailman.qth.net>; "Old Tube Radios" 
<boatanchors at theporch.com>
Sent: Saturday, November 26, 2011 11:14 AM
Subject: Re: Early "Heath Company" Aircraft...

>.... I know where there is one like it - or almost like it
> - and that's on my shelf, waiting for me to noodle it out.   However
> mine is market "HT-4", and I'm really curious now to know what the
> differences in your HT-4B3 are.
>
> I posted some pics here:
> http://smg.photobucket.com/albums/v652/ranickel/Heath%20HT-4/

This is very cool, Robert, because yours was built for an external
power supply, while this little HT-4-B3 was built on the same chassis,
but with miniature tubes and designed to be run entirely from
one of those 90V / 1.5V batteries.

Here's the HT-4-B3:
http://home.netcom.com/~arc5/HEATHAIR/HeathHT4B3.jpg
http://home.netcom.com/~arc5/HEATHAIR/IMG_1044.JPG
http://home.netcom.com/~arc5/HEATHAIR/IMG_1045.JPG
http://home.netcom.com/~arc5/HEATHAIR/IMG_1046.JPG

Note the special minature tube sockets that were built to
fit in the octal holes.  The rear octal socket is used just
for its tie points, and you can see the empty holes where
 the filter cap and relay would have mounted.
 The little critter works just fine and sounds excellent.
I'm using the "trailing" antenna postion, since it assumes
something at least close to a resonant antenna.
I tuned-up the little rig into a 50-ohm dummy load
with no problem.  Appears to be 1T4 Oscillator,
3A4 Power Amplifier and 3A4 Modulator.
I have not yet traced the circuit.

Bonus:  I found the "Heath" Miessner MA-4 receiver.
Its face is not nearly so nice and there is battery leakage
damage, but the inside is nice.
I think I know what the next project is going to be....

http://home.netcom.com/~arc5/HEATHAIR/IMG_1038.JPG
http://home.netcom.com/~arc5/HEATHAIR/IMG_1039.JPG
http://home.netcom.com/~arc5/HEATHAIR/IMG_1042.JPG
http://home.netcom.com/~arc5/HEATHAIR/IMG_1043.JPG

73 Dave AB5S