looking for dds vfo with bcd outputs to switch a band pass filter for Juma RX1.

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Robert Holsti:
I have been looking all over the internet for a dds vfo that has bcd outputs that I can use to switch in band pass filters for each band
that the vfo is tuned to. I dont know how to make my own pic code to make one do what I want it to do.

I am modifying a Juma RX1 receiver. The receiver only covers 40 meters and down but I want more coverage.
I removed the original dds vfo and replaced it with one from N3ZI  and it is a exact match physicaly to mount above the receiver board.

It works like a champ and covers all bands but It only has one bit that I can switch so It will only switch two band pass filters. I put a rather big band pass filter in for 20 meters from KitsAndParts and was realy surprised of how well it worked. I was also able to pick up some 15 meter signals but rather weak for an obvious reason.

 I have a band pass filter kit on the way from Kess K5BCQ  www.qsl.net/k5bcq/Kits/Kits.html 
that I will use in the small radio, so instead of using a seperate bcd switch, I sure would like to have a VFO that has band switching output that I can use. So, any one out there have a good source to what I am looking for?

I know I can make my own, but would rather use what is out there, life is short and dont want to spend that time playing around designing something.

Robert KH2BR

Robert KH2BR

Dale R. Parfitt:
Have you looked at Jim Hagerty'y DDS? I see he now has bandswitch input and you could likely use his DDS and this board  to control your filters:
http://www.wa1ffl.com/rotaryVFOcontrol.html

Let us know how you progress.
Dale W4OP

Robert Holsti:
Hi Dale,


Thanks for the fast response and info. I checked it out and the price is way to steep and with the add on board for band switching, you still have a knob to twist and the only knob I want to turn would be the vfo knob.

PA0KLT at sdr-kits has a SI570 vfo that has outputs for band switching and it goes down to 3.5mhz but, output is a square wave and additional LP filtering would be needed due to harmonics.There also other buttons to add.  I would like to use the vfo with a transmitter and not have to worry about harmonics. I could give it a try. I saw that price and said WOW !!  cost more then the Juma RX1 and the N3ZI dds cost me $45 bucks. so I need to keep the cost down. It should not be to hard to add bcd band switching outputs to a pic and not cost that much. I may be forced to make my own.

73's, Robert KH2BR

Floyd Sense:
Way out of the price range you stated, but check out the IQPro DDS VFO.  I'm aware of the other DDS VFO kits and use one of them as well, but the IQPro design covers all the bases and can control external relays for band switching.  Plus, the source code is available free from the author.  That might give you some ideas on doing your own thing.

73, K8AC

Peter Gant:
This isn't exactly what you're looking for because the outputs to switch the bandpass filters are not in binary, but it might give you some clues.

http://www.analog.com/static/imported-files/application_notes/AN-557.pdf

Tanakasan

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