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Regarding the Bitx40 spur, I previously wrote: It's possible that a low pass filter on the VFO is sufficient, allowing through 4.8mhz but not the harmonic at 19.2 mhz.? However, the diode ring mixer

There is a way in which the Bitx40 can produce a spur, as Brian reports. Look over the last few posts in this thread: ? ??/g/BITX20/message/21998 The thread has to do with images

In Europe the birdey on 7.2Mhz is a nice end of band signal? Rob

It was a? very easy swap with the relays. They came to me im Europe from Alibaba in 3 weeks 18$ for 10. 5 for my friend. Taking the old ones out with normal solder pump. Just one of the old relays

Don't say that John. It was never our intention to spam him. Perhaps he is impatient that Ashar Farhan did not reply to his query, but all others. After all he is also like all of us. I was dam

FolksAs you modify these PCB's to correct spurs and such remember; Adding new?PCB's and or daughter boards often inject new noise sources.and may disrupt existing signals.? Placement? and integrity

All good info, I did not wish to stir up a hornet's nest.? Remember this rig is not produced by a full-time, for-profit enterprise.? Please respect the efforts by lots of people world-wide as we

I have double checked the connector... I'm confused... Doesn't take much to do that. ________________________________ Sent: 05 December 2018 00:38 To: [email protected] Subject: Re: [BITX20] UbitX

I had a couple of QSOs on 7.177mhz looking for QRP. None of them was. On 7.277 there were only strong AM stations at least here in the Euro side. To be on the safe side a General should call at 7.178.

I suspect that RF is getting into the base emitter junction and causing problems.? The preamp was designed to be located inside of the microphone with nearly zero lead length between the mic

As for older boards that need relay replacement I have to say they were all but an easy swap. Using just a solder iron, copper braid and a pump I could not remove any of them. They were useful but not

Brian, So when operating between 7.1 and 7.3 mhz on the Bitx40 we have a transmit spur at 7.2mhz? That would be weird, especially if the spur didn't move as we tuned across that range. The receive

Bret try ubitx calibration or zerobeat into search engine, that should take you to hfsignals page. My bfo setting was way off, I needed a clue on it to get it close enough to align. If you happen to

Bret, you may start calibration here?http://ubitx.net/2018/03/22/calibrating-your-ubitx/? and wiring according to the enclosed sketch. 73 Axel

Between Raj and Farhan, we have some nice minimalist solutions for spurs. A number of fixes for the harmonics have been proposed, I like swapping out the relays if that works well enough.? If

I will listen to 7180 but find it crowded on Sunday afternoon at times. 40 can be bad with AM Carriers. 7.285 is a fairly recognized qrp frequency. I had a 20m qso last Sunday on 14.285 They were in

Bret try ubitx calibration or zerobeat into search engine, that should take you to hfsignals page. My bfo setting was way off, I needed a clue on it to get it close enough to align. If you happen to

Well after a year I have finally got my radio in the cabinet and now I'm ready to calibrate the zero beat and BFO and wouldn't you know it I can't find the calibration documention.? I also have the

The AXICOM relays mounted on sockets is as bad as the original. They must be soldered direct on PCB. This I have confirmed on two boards. Raj

Jerry, The 45MHz filter fix of mine and the LP filter of Farhans does the same thing. It cleans up the act only on the higher bands. I tested it on a new board last week. Change to AXICOM relays is a