1. change the band pass filter to 28 mhz. take the tap off the antenna end of band pass filter, modify the sktech to work on 28 mhz and you have the base of your transverter ready.
2. look around the vhf/uhf books and find stripline filter that makes a bandpass filter with just an etched FR4 board. no tuning really needed. now, add two 1N4148 as anti-parallel diodes, take an additional clock output of the raduino running at 202 MHz and use it as the LO (the anti-parallel mixer needs the vfo to be at half the LO frequency). you are on 70 cm!
3. to improve noise figure add a one dollar MAV-11 or MAR6, between the mixer and the band pass filter. Wow, now you are transmitting a full milliwatt
if this is all too cumbersome, just go and buy an RFM22B for three dollars. you don't know what that is? have you been living under a stone?
On Sun, May 28, 2017 at 11:23 PM, David Woodward <kf4wbj2@...> wrote:
Yes I have one also...I made a moxon out of coat hangers and regularly work the fm sats...what I want is to work some ssb says like ao-7....
I have an rtl- sdr for receiving via sdr console v2.
I'm thinking of converting the BITX40 to 10 meters and using one of those Russian transverters for xmit...
On May 28, 2017 10:20 AM, "Jamie Rolfe" <j.rolfe8@...> wrote:
Hi David,?
I know.? These Bitx40 kits are excellent.? Glad you're having fun. It took me more time to make a box than to get on the air.?
If you want to get on 70cm cheaply I suggest the Baofeng uv-5r. They are an HT that run about $39. I've had mine for about 4 months and I've only had to charge it twice with stock battery. Accessories are super cheap online as well.?
