开云体育

Hi Jim, There is no need any more to restrict sales to the 48 CONtigious United States via USPS. The priority and flat rate shipping is good for ALL states and any US territories. That includes the

I have too many radios! (like 6 transceivers, including another uBITX)? This is a version 4 uBITX in a nice case (Fry's).? It has a 2.8" Nextion display, AGC/S meter, Axicom relays, and an LM386

Electret and Ceramic are two different types AFAIK. Electret is not AKA ceramic.

Thank you, Timothy It seems that the mic may be the underlying cause and if I have connected it in reverse polarity I may have damaged it. Then testing with a damaged mic has invalidated all the tests

On a related matter, the? heat sink of the IRF 510 on this tcvr and also on the uBitx? is live to ground ( It's a feature !!) Bear that in mind when working on it or casing it.? The Fuse on the

Polarity it critical. There is a small Linear IC equiv approx to? a u741 built into the mic insert.? ?Generally one of the mic solder tabs on the back will? be marked with a posittive to show

Thank you, Jakobus I am at the office at the moment. I will check polarity as soon as i get home Regards Gary ZS5GI

Yes it is polarity concious. If you look at the capsule 2 connection pads, you will see that one of them have tracks to the casing. That is the negative one. The one that has no tracks to the casing

Thank you , Timothy I am not using a Dynamic mike, I am using the small electret mike as was supplied with the kit. I make up the mic with a plastic enclosure and a switch for the PTT. 4 wires, 2 for

jerry, i built it so i could stuff it inside the cubesat to measure the antenna. an external spectrum analyzer and its cables were upsetting the RF model hence, i needed something that could read the

On second thoughts, you replaced the main? board ( I re read earlier post) . The chance of having two bad K1 relays seems remote - depending on what voltage you are running the thing on and how much

Gary , JG has done a v good job of pointing out where you are at the moment. My tuppence worth and this is not very systematic is that if relay K1 has failed or the PTT line is not getting earthed

Thank you , Jerry. I am going to try a completly new mike, including the wires to the jumper on the main board. I also thought that I could try a CW transmission test if I wire up the CW keyer. ??? PS

Farhan, OK. so best thought of as a basic spectrum analyzer Has a return loss bridge up front to measure SWR. Not weird at all. But does look very cheap and buildable. I've been thinking of building a

That sounds like a broken mike connector. Since it receives, the si5351 on the Raduino is doing everything it needs to on transmit. When the Bitx40 transmits, it switches off power to the receiver

The AQRP Vector Impedance Analyzer, kit #25 towards the bottom of this webpage: ? ??https://www.qsl.net/k5bcq/Kits/Kits.html does something similar, but at audio frequencies.? K5BCQ also did the

Bitx40 - was working, but now does not transmit audio. The device was working well with many QSOs on 40m. All of a sudden it does not transmitt any audio. Receiving is excellent. To test or trouble

jerry, first, thanks. there is substantially your code in there. second, onto the circuit. it uses two clocks. not three. the third is a spare output. more on that later. the circuit here uses a

Jerry, I remember Farhan mentioning that the clock out of the Si chip is not clean and will cause wrong readings due to harmonics. To solve this, mix down and pass through a filter and then take the

My ADE-1 document just says that pins 1,4,5 are all ground,? 3 is RF, 6 is LO, and 2 is IF. out. Your schematic suggests that 4 is only the "ground" for the RF port, and is not connected to the other