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Fernando LW5DNC I have built a BITX20, a BITX40, and am slowly working on a BITX-LF for the US LF band (160 to 190 KHz). Farhan VU3ICQ's original design seems easy to modify for other bands (there

HELLOW FOLKS : ANYBODY IS EXPERIMENTING WITH BITX IN 80 MTS ? BEST REGARDS FERNANDO CASARI LW5DNC ARGENTINA

Hi BITX-ers, Just when I thougth the job was done I discovered problems in the PA stage: output when there was no modulation. First I read all the messages of this subject posted in the past in

Ron If it is really AM, then check the diodes to make sure both are still good, and that one is not in backwards. If it is DSB, then verify that your carrier oscillator is about 400 Hz down the

Dear BITX'ers, Just did some trials with the BITX17 transmit section (no PA installed yet). I am a bit puzzled now. When I switch on the TX (no modulation yet) I can hear 2 sidebands on my Philips

Counterfeit electronics. < http://sound.westhost.com/counterfeit.htm > Jim N6OTQ

Hi Julius, if you build only the receiving part, you do not need to make the bi- amps. You can do with single amps. However, then a value of the resistor needs to be changed. You can find that out

hi chris, you are truly right, i am still in the process of learning about this, not changing the original schematics is already confusing me, but i am begining to understand the building blocks of a

Hello Julius, the question you asked is indeed answered by Arv. However, my concern is that this is should be common knowledge of a licened radio amateur that you do not seems to have. I am affraid

I use a 2N2219 instead of the 2N2218. The power coming to this transistor is very very low. The 2N2219 is really boosting it to a level the IRF510 can be driven. In the Fies/Modifications chapter

Ruud & Chris In my original BITX20 I used 2N2222 transistors for most of the stages and found the performance to be really poor. After checking the gain of various stages I substituted 2N3904

Hi Ruud/Chris and rest of BITX group, Talking about transistors in the TX chain: Finished most of the tx chain of my bitx17 yesterday evening (at this moment still without pa stage). I connected 2

Julius 5.0 to 5.4 MHz might be a better choice for VFO frequency because it is much easier to build a stable VFO for 5 MHz than it is for 23 MHz. Even applying a Huff & Puff stabiliser circuit for

hi chris, i am bit confuse on how to measure this crystal filer (still learning :) ), i had this 9MHz Crystal filter with 2.3KHz filtering bandwidth, lets say that this filter works fine, while i'm

Hi Chris, A second reaction on your remark about the 2N3866's in the driver- stage. I looked it up to be sure. You are right: the voltage gain and power gain are defined by the resistor values

Hi Julius, what is important for a filter is that the input and output impedance and capacitance is correct. A very good filter that is shunted the wrong way gives likely a poor filter shape. So

Please look at the shape of that filter. As I understood, it will always be one peak. Not really suitable for SSB I think. Good luck, Chris. filters and JF1OZL was problems

hi, i am just starting to built my own homebrew radio, actually, i found that this is enjoying, and a good hobby because usually i only work with electronics on audi amps, tv and stuff, not radio, in

Hi Arv, Thanks for your message. I planned some experiments with the filters and the SpectrumAnalyzer when I finished the BITX20. The filter of JF1OZL was new for me. I will try that

About RF PA I can say that recently I had to make a little linear (A class) amplifier and had an old 2N3553 in my junk-box. I found it very good and flat up to 45-50 MHz, a good power amplification