[AMRadio] Old Ham, New AM Enthusiast

[Larry Szendrei]

On 12/27/2010 1:24 PM, rbethman wrote:
> Jerry,
>
> You are getting good advice - so far!
>
> One other made comment regarding the Apache.  It has a "well earned"
> nickname. * Scratchy Apache *
>
> It take a bunch of work reworking the audio circuitry to make it sound
> like "you" REALLY sound.
>
> It also REALLY needs negative feedback added in.
>

I used to have an Apache. When I bought it, the modulators had been 
converted to triode-connected 6146s driven by outboard audio*. The thing 
sounded very, very good. The only thing that was used from the original 
Apache audio section was the modulation transformer, which isn't a bad 
piece of iron.

*This is what the audio section looked like:
  -push-pull tube type audio output xfmr with 8 ohm speaker winding as 
audio input from external audio amplifier capable of at least 5-8W 
output. (original) high-Z primary ends go to 6146 modulator tube screen 
grids, and center-tap of this winding goes to ground.
  -6146 modulator control grids tied to about -5V bias, well bypassed 
for audio and RF, to put the operating point for the modulator tubes in 
a good place.
  -6146 plates to each end of mod tranny primary per usual arrangement.
  - voila! quick and easy good audio for the Apache!

Having said that, though, I agree with Rob about focusing on the antenna 
first, and spend some time on AM before deciding what the  "upgraded" AM 
station will be.

Here are some AM nets up here in the Northeast you might be interested 
in checking into:

AM Carrier Net, Sundays at 8:30AM on 3835 KHz
Antique Wireless Association Sunday PM AM net, Sundays at 4:00PM on 3837 
KHz.
Gray Hair Net, Tuesday evenings at 8:00 PM EST (or 8:30PM EDT) on 1945 KHz.

73 and we'll be looking for you Jerry,
-Larry/NE1S