[hpsdr] Control an FT-1000D Low Pass Filter assembly with PSDRmouse?

[ct1izu]

I use BC640 PNP switches, you might cross check the max limits of the 2N907 against these.  

I use 3k3 buss resistors in the Penny DB25 line and 2k2 in the supply to base for same reason as Phil suggested.
It should be a compact layout on Vero or perf board. Make sure the supply properly decoulped to avoid modulating the switch lines.

Shel CT1IZU


----- Original Message ----- 
  From: Tom Cathey 
  To: hpsdr at lists.openhpsdr.org 
  Sent: Friday, March 04, 2011 2:21 AM
  Subject: Re: [hpsdr] Control an FT-1000D Low Pass Filter assembly with PSDRmouse?


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  Thanks for the info, Joe and Phil.

  Yes, I need 9V high switched to the relays at 100 ma per band.  The relays are grounded on the board.    I see the connections coming off the Penny 25 pin connector on the schematic. Also see the software toggles required.  Good.

  That circuit looks good, Joe. Though after a quick look, the M54581 chip is $20 and only available from the UK. 

  I was thinking an easier way might be to use a small 2N2907 PNP transistor which gets its base grounded from Penny, the collector to 9V and the emitter in series with the LP relay.  I would need one transistor per band, or about seven transistors total. Not too bad.   

  Does this sound like it would work OK?


  Tom, K1JJ



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