Sunday, April 09, 2017

More filters III - "Telrad" board".

Just another update to these filters and boards as on More filters I and update II

Found the page of GW4SAE/ZL4SAE with an updated schematic of the board, no question, Will made an excellent work.

Basically just confirms the schematic from here as referenced on the previous post about this boards.

Also in regards to the filters in the board, some time ago I found the following: (From here and here)

XF-9 S 44
XF-9 S 42
XF-9 S 43

S42: bande passante=+/- 3k6 à -3db : fréquence centrale 9.000000 MHZ
S43: +/-1K55 à -3db : 8.998200 MHZ
S44: +/-1K55 à -3db : 9.001800 MHZ

Capa d'entrée et de sortie: 25 pF
Z entrée/sortie 560 ohms (mesurés)  ..."

In the mean time I started to prepare the board to make also some experiments, maybe a future receiver.

Backside of board:

Removing the extra hardware:

Have a nice week!

P.S. Just made a small jig to take on the underside the audio amp, bfo and vfo for further testing, time permits:

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