Keyboard Shortcuts
Likes
Search
Bad TX audio SOLVED. Not fixed.
|
The buzzy audio was the DDS VFO was way off frequency. When separately powering the PA it kept going into calibration mode half of the time. When powered by the same 12v supply I could not get it to go into calibration mode by shorting the 8 pin connector brown wire to ground. Shorting it seemed to do nothing at all. But now it is fried. The top line of display flickered with buzzing from speaker. Unplugging a few times got the top line of display to all solid blocks, and the "L" LED on the nano is blinking and a click is heard from speaker in sync with blinking. Before this, a friend was listening for my signal and never heard it. I didn't hear him until I tuned around. Indicating it needed calibrating. Now it's dead. I never got to use it. Now what? |
|
Jack Purdum
Which DDS are you using? Jack, W8TEE From: John Smith via Groups.Io <johnlinux77@...> To: [email protected] Sent: Monday, January 16, 2017 6:43 PM Subject: [BITX20] Bad TX audio SOLVED. Not fixed. The buzzy audio was the DDS VFO was way off frequency. When separately powering the PA it kept going into calibration mode half of the time. When powered by the same 12v supply I could not get it to go into calibration mode by shorting the 8 pin connector brown wire to ground. Shorting it seemed to do nothing at all. But now it is fried. The top line of display flickered with buzzing from speaker. Unplugging a few times got the top line of display to all solid blocks, and the "L" LED on the nano is blinking and a click is heard from speaker in sync with blinking. Before this, a friend was listening for my signal and never heard it. I didn't hear him until I tuned around. Indicating it needed calibrating. Now it's dead. I never got to use it. Now what?
|
|
Looking back at your previous posts, sounds like you are using some sort of DC-to-DC converter to get 12v. ?And if so, then Raj likely called it right when he said you had converter noise. ?It could be that this DC-to-DC converter was outside its spec when you tried to transmit, and when you stopped transmitting there was a voltage surge that damaged the radio. ?(Spec's on $3 ebay boost mode switchers tend to be rather generous, so when it says 3A and adjustable up to 12V, that does not necessarily mean it will do 3A and 12V at the same time.) ?I'm guessing here, as you have not told us what radio you have, what VFO, what this 12v DC power supply is, what knobs you have twiddled on that DC supply, etc... I'd recommend starting out with batteries, not some switching power supply. ?Ideally something capable of at least a couple Amps, like a motorcycle battery. ?With a 2 Amp fuse in-line. ? And if you have trouble with the Raduino, then back off to the analog VFO by installing the coil. ?But all that advice might be a bit too late here. In answer to the original question, this is your Bitx40 customer service. Jerry, KE7ER ? |
|
You should look closer at my previous posts.??I have used a 12v battery pack, and 12v 1.2A converter. Then I connected a 12.6V 4A converter for radio, and PA. Finally powering the PA with a 20v 4A separately. There was no difference is noise from the battery on up to the 20v 4A supply. But there was a difference when I tuned the bitx from 7.8500 to 7.8350?while receiving on 7.850 on a SSB SW receiver with all settings set to normal, not DX and the antenna retracted. And SSB tuned for most natural tone, and the received audio was weaker than expected. Now it's all over, it was obvious I was transmitting on a different frequency than I was monitoring. Like when I tuned up and down for my friends transmission.?I was only able to hear mine because of the close proximity. Now, how do I get a replacement?
|
|
OK, I've looked through all the posts in "Bad TX audio" and "Bad TX audio SOVLED. Not Fixed." ?Perhaps there was some other thread here. ?I do now see where you said "Raduino". ?I'm still curious what these converters are, and a bit suspicious that they are at least part of the trouble. ?And curious whether you really meant to be operating at 7.85 on a radio designed for use in the ham bands. ?And not really sure what state the radio is in now. ?Perhaps you need to find somebody else here to help you. I have not yet received my Bitx40. ?If it fails, I'll try to fix it, perhaps with help from the group here. ?That's what I meant by "this is your Bitx40 customer service". ?I doubt I'll be asking the folks at hfsigs to replace it. ?You're welcome to try. . Jerry, KE7ER |
|
Oops. I meant 7.0850. If you listen to a signal close to the one you are on, it will not sound full strength, and not clear. This is what I was experiencing until I tuned the bitx down a bit. Then is sounded pretty normal on my SW radio. And just for a second when I tuned past where my friend was. He was on 7.0850 with a icom 706 mk2g. So, the raduino was way off the displayed frequency. There are instructions on hfsigs.com under "wire up" at the bottom of the page for calibrating the raduino frequency. Shorting the brown wire did nothing. But calibration mode came on at start up with the higher power adapter in use. You can't calibrate it that way. And the adapters are newish switching power supplies for LCD monitors "12v". And a laptop at"19v" but jives 20v. They are very precisely regulated and quiet. On other projects, I have used switching buck converters which can be very noisy at certain voltages. And a PC power supply for bench top power for transceivers are also very noisy. So I know what that is, and how to avoid it. My only problem with TX audio was not transmiting on the frequency being monitored at home and while my friend was listening for me. And transmitting back. He didn't have long to do this the other night. I did not know I had to calibrate it first out of the box. I just trusted it. But none of this changes the fact that my raduino is not working at all. Except for the "L" LED blinking and solid blocks displayed on the top row of the LCD display. And just a hiss coming from the speaker with coresponding click with the blinks. It never worked right, and It's completely busted! And I made sure of it before going through all of this.
|