[TenTec] FS 285 & 217 500Hz CW filters

[Ken Brown]

Some of Ten-Tec's filters have both the model number and the stock code 
stamped on them. Some have only the model number. Most I have seen have 
only the stock code. In many cases only some portion of the stock code 
is legible. Some of them have color marks on the crystals, such as blue 
green or red. My guess is that the colors were used when sorting the 
crystals by frequency.
> See http://www.tentecwiki.org/doku.php?id=filters
> My filters have the numbers 285 and 217 on them, as well as the stock code numbers
>
>
> i have several of these filters.  can you tell me how to tell which is which
> tentec doesn tmark them.
>
>   
Ten-Tec IF filter data

Model Number / Stock Code / Bandwidth Hz / Center frequency MHz / Poles

216 / 48161 /  500 / 9.002210 / 6 RTTY filter
217 / 48036 /  500 / 9.000750 / 8
218 / 48037 / 1800 / 9.001500 / 8
219 / 48055 /  250 / 9.000750 / 6 /8047 / 6840
??? / 48057 / 2400 / 9.001500 / 4/ Corsair 2.4 kHz stock filter
220 / 48058 / 2400 / 9.001500 / 8 /8307 / 6840 Omni stock filter
221 / 48243 /  250 / 9.000500 / 6 Low note CW filter
282 / 48054 /  250 / 6.299250 / 6
285 / 48053 /  500 / 6.299250 / 6
288 / 48075 / 1800 / 6.300000 / 8 / 9125 / N5
unk / 48127 / 6000 / 9 / ? / Paragon AM filter??
unk / 48074 / 2400 / 6.3 / 8 / Stock (non-option) 6.3 MHz filter>

The Model 220, stock number 48058 is the "normal" stock 9 MHz filter in 
the Omni VI. It is used for opposite sideband rejection and bandwidth 
limiting in transmit, and as the non-narrow (neither NAR or N-1 or N-2) 
receive filter. It is probably used for the same purpose in some other 
Ten-Tec equipment.