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I doubt my previous suggestion of "Swap pins 3 and 5 of relay K2, add a 100k resistor from K2-1 to ground" would do anything but make the transition noisier.

Isn't it better to drive a diode-ring mixer with a square-wave local oscillator? You're wanting to switch the diode pairs hard on, then hard off. Steve G3TXQ

Any thoughts on the 'proper' selection of a low-pass filter for the output of an Si5351? Is it sane to think about a 60 meter low pass for the 4.7-5 MHz, or would most anything work to clean the

Would You please upload a photo which shows the points you use ? Thanks in advance Walter Dortmund, Germany

Here's what I did - I tapped the TX / RX +12 points from the relay closest to the Power Connector. This will give you +12 on RX, then on PTT, RX goes to zero (or nearly) and TX goes +12. This way,

2 weeks to ship for free from India to Indiana, awesome! [cid:image001.jpg@...][cid:image002.jpg@...] [cid:image003.jpg@...]

Good question regarding why D18 is in there. The diodes are needed on the bidi RF amps, as Ashhar notes in his circuit description: "The diodes in the collectors prevent the switched-off

randy, post it to me directly at farhanbox@... and i will put it up on the bitxhacks blog, thanks for the effort! - f BITX20@...> wrote:

Hi I was looking over the BITX 40 schematic last night before watching Farhan on Tom's W5KUB show. At first, I was a bit confused with the signals flowing back and forth around the two-way amps. I

Hi Jerry, Assume RX is pulled to ground by K1 relay. Would it be a solution to discharge via diode/resistance combination just in front of D18. What’s the actual use of D18 btw? Ron –

Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20 group. File : /K7AGE/BITX 40 transmit signal path.pdf Uploaded

Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20 group. File : /K7AGE/BITX 40 receive signal path.pdf Uploaded

A few possibilities: Swap pins 3 and 5 of relay K2, add a 100k resistor from K2-1 to ground. The resistor slows down the falling edge there to avoid a pop in the speaker, the 100k should

Hi, Experience a long PTT switch over time, resulting in a extended RX audio. Ashhar mentioned this probably is caused by the large uF in the audio amp circuit in yesterdays Amateur Round table

Jorge, This is normal. As the final IRF warms up the current increases. Do not worry!

OK thanks Joel and Ken, nearly all set, just need a power connector and a couple of knobs in the morning. 73 Dave

Don't plug anything into the DDS connector. The tuning potentiometer plugs into the connector marked 'Tuning'. All other connectors are the same hook up. When you get your Raduino, disconnect the

David, If you would like to try it out while waiting for your Raduino, just don't hook anything to the DDS connector and hook up the tuning pot to the tuning connector. This is assuming you haven't

Ken, That link comes up with the new diagram with the DDS. I have one plug left over with a spare connector in the middle of the board. In the latest diagram that goes to the DDS. Is it used for the

Yes .measured rf voltages i am getting 200 mv compared with working one 500 mv on my cro in c132 .all stages up to q4 base only 30 % of working one . During comparison i am using same mic ,same power