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Old March 11th 05, 06:39 PM
Bob Liesenfeld
 
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Michael wrote:

Anyone know the difference between the 2515 and the 2515A?

I wonder who built this rcvr? Trio maybe?

Thanks


The main difference is in the IF strip. The 2515 uses 4 of the
filters in the IF while the "A" only uses 2. I believe one stage IF amp
stage was dropped in the "A" model as well. Another minor difference is
in the RF amp. In the 2515 the bias on gate 2 of the dual gate MOSFET
is fixed with a voltage divider, while in the "A" a variable resistor is
added into the network, so as to be able to vary the bias over a small
range.
I remember using the 2515 as a SWL rx back in the late 60's and finding
the 4 IF filters to be too much selectivity for AM broadcasts, and not
quite enough for CW/SSB. The "A" model having fewer cans fared better
with AM.
Those cans were a mystery as well. I don't think they were Toko
products but I don't know for sure. I opened one up once and found what
appears to be a ceramic filter disk and an unusual arrangement of coils.

These radio were sold by Allied Radio. I have not been able to
determine who actually made them. I once corresponded with a Trio
employee who worked there about the time these units were being sold,
and he swore they were not one of theirs.

Bob