[AMRadio] RE: Receiver update.

[Brett Gazdzinski]

Hello all AM'ers.
My home brew receiver is coming along.
I got the LO working well, the mixer works also,
that surprised me!
I built 3 stages of IF amplification, and did experiments
with circuit values and component types.
I had some sort of oscillation at times, caused by excessive
plate voltage on the tubes and un-grounded IF transformer cans.

I also tried the mechanical filter I have, and it seems to work
well but is somewhat lossy...need to experiment a bit with that.

A good spectrum analyzer has been incredibly helpful, and
I am lucky to have a very good one through work.
It enables me to see things, measure things, and makes a great
frequency counter as well.

I am working on the detector now, and may be able to actually
listen to something soon.
The RF amp is waiting for coil stock, so that will be a while,
but the receiver picks up the signal generator
turned all the way down and not hooked up to the receiver.

I still have the agc, S meter, manual IF gain control, 
manual RF gain control, muting circuits, and the rf amp 
tuned circuits to do, but I am surprised its coming along
as well as it is.

Anyone got any good octal TUBE type detector circuits?
I have one off the web, low distortion am detector,
but it does not list the tube types.
Its a diode (tube) followed by a triode amp, output 
taken off the cathode and the rf filtered out.

Tonight, my Scott SLRM blew out its mixer tube filament
while listening to 80 meters.
Its been a long time since I blew a tube out in anything.

Figures its one I don't have a spare for (12SA7)!


Brett
N2DTS