[Collins] Filter I.D.

[Dr. Gerald N. Johnson]

2.8 Khz bandwidth is a good guess except for the Z filters. There the 
last digits don't show the bandwidth. Often in the Z family the 
frequency is carrier for SSB and the numbers refer to a list of Z family 
filters. Like Z4 and Z5 are USB and LSB 3.3 kHz filters for 455 Khz 
carrier frequency. Any other letters in that position signify the case, 
but not the Z filters, some early Z filters are in a C case, some are in 
a Y case.

Found a sheet dated October 1983 in my Collins folder. It says a 
526-9698-010 is: 455 kHz carrier frequency. 3.30 kHz 3 dB bandwidth, 
4.80 kHz 60 dB bandwidth, 2K source and load impedance for USB in the FD 
case. The FD plastic case is the same size and connections as the FA 
that came out in the later S-line gear, but without the threaded 
mounting studs. This chart doesn't list the model numbers, just the part 
numbers and the very condensed specifications. About 141 different 
filters for 450, 455, and 500 kHz. And only Disk-Wire types, not torsional.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association

On 3/28/2011 3:18 PM, David Pritchard wrote:
> Hello,
>
> I recently came into a number of older Collins mechanical filters. The
> P/N is 526-9698-010. Some of the filters are also marked F455 Z 28F. The
> dates codes are all 1977 - 1978. I have no way of testing the filters
> but am guessing they are 2.8 Khz. wide IF filters. The part number does
> not show up in any Collins literature I can find.
>
> I'd appreciate any information anyone might have about exactly what
> these filters were used for.
>
> Dave
> W9QL
>
>