[Amps] Ameritron ALS 500M

[Mike Feher]

Al -

Interesting comment. It will be easy enough to measure the two tone IMD as a
function of voltage. I assume the higher order ones will not matter as they
should be pretty far down, but, possibly the first and 2nd order may be
worth a look. It is interesting that almost all HF radios in the 100 to 200
watt class are solid state running off of 12 volts. I know in those the 12
volts is not regulated or preset to any specific value. In fact, I also have
a Kenwood TR-450SAT with matching PS-30 power supply. That is about the
worst supply I have ever seen as far as regulation goes. I would think your
comment would apply to all those rigs as well. 73 - Mike 

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 


-----Original Message-----
From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Al Kozakiewicz
Sent: Monday, November 23, 2015 10:04 AM
To: amps at contesting.com
Subject: Re: [Amps] Ameritron ALS 500M

The glaring defect of this amplifier is that it runs on 12v and my
understanding is that IMD is thus highly sensitive to supply voltage, i.e. a
fraction of a volt change can improve the IMD from really bad to just plain
bad.  Any amplifier final is a slave to the transfer curve.

As a compromise device for the intended HF mobile use it's the only game in
town AFAIK.  As a fixed station amplifier it's not a great choice, though
for continuous modes like CW IMD really doesn't matter.

IMHO. YMMV. LSMFT.

Al
AB2ZY