I've been using a SB-200 with various rigs (C.E. 100V, Laf. HA-410 (on
10, when 10 was hot), Icom 756 PRO II, Icom IC-706 MKIIG, Johnson Ranger,
and Kenwood Twins on AM for the last 15 years. Sometimes I use the
Johnson Courier as an alternative to the SB-200. Courier also runs with
572B's. Simple to use, simple to interface, provide an extra fan on top
of the SB-200 to exhaust the heat. The SB-200 is a great workhorse. Still
using the same 572B's that were put in it in 1969. I generally run the
output between 100 and 130 watts.
Pete, wa2cwa
On Sat, 18 Mar 2006 07:48:02 -0800 (PST) Jose HF Silva
[EMAIL PROTECTED] writes:
Hi,
I have been using this combination and got some good
reports but I have not a reasonable idea of power
output.
So I would like to have a good estimation from those
who are better prepared to do it.
Thanks^6
73 de Jose' CT1AXG
Date: Fri, 17 Mar 2006 22:03:50 -0500
From: kenw2dtc [EMAIL PROTECTED]
Subject: Re: [AMRadio] Amplifier to use with my DX-60
To: Discussion of AM Radio amradio@mailman.qth.net
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; format=flowed;
charset=windows-1250;
reply-type=response
Don K4KYV said:
I hear a lot of guys on the air with AM linears, and
most of the time
they
claim to be running way too much carrier for the
tubes they are using.
I
often hear stuff like 200 watts out with a pair of
811A's or 250 watts
out
with a pair of 813's in g-g. If so, they are cooking
the tubes, or
else the
efficiency is running too high, and they are
flat-topping all over the
place.
I agree with your comments and yes, there is no doubt
that those rigs
are
flat-topping. I've been running linear amps on AM for
years and I find
that
the cleanest, best sounding signal comes from a
linear with LOTS OF
PLATE
DISSIPATION and HEADROOM. In addition, an audio
signal generator and
an
oscilloscope are mandatory to get clean results. Not
everyone has this
equipment and it is a hobby after all so folks do the
best they can.
As a rule of thumb I consider the plate dissipation
divided by 3 to be
a
general yardstick for AM linears, some tubes giving a
little more and
some a
little less. In the case of a pair of 3-500Z's I rate
them in the
333-350
watt carrier class. So while a pair of 813's can be a
wonderful plate
modulated rig, as an AM linear they are not worth all
the trouble of
building them. It seems to me to be a waste of time
to build an AM
linear
with much less than 1000 watts of plate dissipation.
Of course if you
have
a low power rice box and already own some kind of
linear, well go
ahead, but
if one is building an AM linear, more dissipation is
better.
73,
Ken W2DTC
