[TenTec] Argosy 525 identification: three different receiver mixersand serial numbers

[Kevin Purcell <kevinpurcell@pobox.com>]

The current list with contributions from: VE7BGP, WA3FIY, N4NT, NN8B  
and NS1W. Thanks too all.

525  00721 1496 (Argosy front panel) VE7BGP
525  00748 1496 (Argosy front panel) NS1W
525  00895 4 diode mixer MBD-101 (Argosy front panel) NN8B
525  ????? 4 diode mixer (Argosy front panel) KW7CD
525  01096 4 diode mixer (TO-92 diodes not marked: probably MBD101)  
WA3FIY
525  01188 4 diode mixer MBD101 WA3FIY
525D 01611 diode quad ND487C1 (Argosy front panel) N7WIM
525D 01810 diode quad ND487C1 (Argosy II front panel) WA3FIY
525D 01892 diode quad 87clk32 (Argosy II front panel) N4NT
525D 02497 diode quad ND487C1 (Argosy II front panel) N7WIM
525D 02591 diode quad ND487C1 (Argosy II front panel) WA3FIY

So the conclusions are:

1. 525 Argosy with serial number 0823 or less has a 1496 for rx mixer.

2. 525 Argosy with serial number 0824 or greater has a discrete 4  
diode ring (most likley using MBD101 schottky diodes) in the rx  
mixer. They didn't use PN diodes unlike say the 546 Omni series.

3. All 525D Argosy have a schottky diode quad ring (even though they  
may have either an Argosy or Argosy II front panel they all have a  
digital display).

4. Somewhere between serial numbers 01611 and 01810 the 525D got a  
new plastic front panel with a different name plate (Argosy II).

The serial number 0823 comes from the change in noise blanker design  
hypothesized to match the mixer type: Model 223 for 0823 or less;  
Model 223A for 0824 or more.
--
73 DE N7WIM / G8UDP
Kevin Purcell
kevinpurcell@pobox.com



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