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SANDRO As promised, here are some measurements from my BITX40 circuit board: AC Signal Measurements: 1) Microphone Amplifier output (Q10 collector) is 8V PP with the input totally

some data from my BITX17: - very low output from the 1st mixer, 0,2 mw after the 22 ohm resistor (one of my first messages in this group). - after Q11 I measure about 1 mw over 50 ohm (I know that

SANDRO What measuring capability do you have available for debugging your BITX? Do you have an oscilloscope? Do you have a high-impedance DC voltmeter? Do you have an audio signal

hello Arv, thank you for the clues I don't have 100mw in the exit... 8 - ( I will verify all the points that you wrote, later I say the result. the transistors are

SANDRO Without the linear amplifier stages you will only get 100 mw to 200 mw power out of your BITX. If your power output is way below that, then here are some places to start looking for the

hello Arv and friends, with relationship to adjust the frequency of resonance of the reels, QSL! mine doubts it is the relationship of turns between primary and secondary to have

SANDRO Like Chris, I used 10.7 MHz IF transformers in my BITX front end. However, there is no reason you could not use appropriate TOKO coils, assuming that they are the proper inductance and turns

Hello Sandro, I am not quit sure that I understand what you ask but I will give it a try. In the 'photos' category, I posted a schematic of what I made for the BITX17. I have seen also a photo for

Jay Trifilar-wound transformers (both toroid cored and air-cored) are a bit different from traditional magnetically coupled transformer designs. In a trifilar-wound transformer the windings

Greetings David, nice to have you aboard. 73 Mike, G8NXD qthr (redruth) --

On Tue, 7 Sep 2004, Mike W wrote: > > Greetings David, nice to have you aboard. > 73 Mike, G8NXD qthr (redruth) > -- > > > On 7 Sep 2004 at 12:03, Pedley David (South Devon Health Care NHS

Hi, I saw the circuit diagram on the internet in July and thought it would be an ideal hf project. I have been collecting all the parts but will not start building it until my Open University course

hello friends, am I building my BITX20 and would it like to use in the front-end reels of FI of the toko, would anybody have the data for the construction? thank you! SANDRO

I doubt braiding would make a noticeable difference. The general idea is to have close coupling between the wires Watch you don't scratch the enamel whichever way you do it. Check for shorts before

Hi all, I have a quick question on the mixer transformers used in the BITX20, I can benefit from others' experience. When I started the trifilar winding I noticed that it is quite easy to "braid"

Chris Thanks for the reply and for your suggestions. I now have the DC switchover working, without any delay circuit, and all seems OK. There is a slight click when changing from TX to RX but that

Hi Arv, I switch by using a toggle switch, which connects the 12 volts to the TX parts (including antenna relay) or the RX parts. Because 'the beep' disappeared by the shielding, I do not see why

Hi Welcome to 100'th member PY2JCM who has just joined! Welcome also to all the other recently joined members. If you are building the BITX20 or are thinking of doing it, and haven't posted here

All, Just wanted to give a quick update on my progress, maybe it will help some of be builders. First of all thanks David for the tips. My air variable capacitor did have a short somewhere

Hi Chris and others, I am happy to say that having built and installed the pre-amp stage, Q14 and put in a little screening around the VFO variable capacitor I have also lost the squeak which was