开云体育

I completed the AA a few months ago, and it has been working perfectly. I found that it really likes clean power, and plenty of it. A regular 9v battery would work for a few scans ?then the unit

That would do it. Jack, W8TEE To: [email protected] Sent: Saturday, August 19, 2017 2:06 PM Subject: Re: [BITX20] Antenna Analyzer problems. Hi Roy, I saw very high SWR where I didnt expect

Dumb question, but have you tried using a different electret mic element ? I had initial low output problems with my Bitx40 using a cheap computer headset with an electret mic element. I switched to

Everyone, I have come up with a modification to Gian's circuit that makes the pop/click completely tolerable with headphones at full volume. Please see the attached modified schematic and report back

Hi Roy, I saw very high SWR where I didnt expect one like the original poster. Then in looking at the schematic again of the analyzer I suddenly realized what was happening ! I was uploading the code

I noticed that later last night (2am) on the M1/M2.. While looking at the drive required for the PTT relay I noticed the RX signal (+12 volt supply to the LM386) is switched by the PTT; Has anyone

Thanks Andy, we'll try what you found.? 73, Karl, KO8S

Specifically what issues are you having? Roy WA0YMH

Hi, Anybody found any solutions or things to trace down the SWR5 problem I am having the same issue it seems...Any help, pointers or tips greatly appreciated. regards and 73 Leo

Hi Karl, I had the same problem with my 40 and after pulling out the transformer, checking all voltages etc, I found that it was the VFO injection. ?Check the voltages on Q7, Q8, Q9 against the

That 190mv at C132 might be ok, will depend on audio level going in. I was seeing 400mv pk-pk when applying 100mv pk-pk at the microphone input to the Bitx40: ?

Hi Jonathan, Check the collector of Q7, it should have a 1 - 1.5V p-p flattened sine wave. Remove C91 and C92 to increase the RF at Q7. Check the value of R46

Change the following resistors R114 from 100K to 220K R112 from 4.7K to 1K This will change the biasing to Q16 taking the collector voltage higher and allowing a larger signal to be amplified

hi Raj! I forgot to add that I had R136 at max setting at C132 i only got around 190mVp-p, Q13 B is 4.06V, C is 12.93V and E is 3.35V? so that confirms I have low signal at C132 (It should be 1Vpp

First check R141 if the value is more than 10 Ohms change it. Many boards report failed R141. At 13.2V DV and 150mV 1Khz audio injection I get C132 = 1 V p-p Q13b = 0.6 Q13c = 12V Preset centered

Hello fellow hams! ? My bitx40 have low output -only about 2 Watts on a dummy load Originally it has only 1W and the receive is OK I had checked and rechecked the TX section (Q13-Q15) All bias

Sorry, M1 and M2 are the other way around. Grounding K2.1 shorts the output of the pre-amp Q16 to earth on transmit, leaving the feed to the volume control and U 1 open-circuit (and probably picking

Can someone try grounding pin 1 of K2? That will take the input of the LM386 to ground when the PTT is pressed. Now pin 1 of K2 appears to be floating in the schematic I have. I've been working on a

Ciao Gian, No worries about the LM386. It still works well. I have spares in the junk box if needed. I was experimenting trying to discover other methods, and thought I would give what I described a

Correction: Nano has 15 pin positions per side