The speech Clipper board has been bypassed. No drop in the receive. It's steady even after an hour of being on. Thank you.
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HELP. PLEASE!!!
- Thread starter Sonar
- Start date
No. I will look at thethe manual in order to see exactly what the r105 is, and what it does. thanks
If the 6au6a is indeed a driver for the V11 6bq5 final I don't think it would affect the audio. I might try it anyway. I do have two backup 6au6a's.
STM. Would you do me a favor? Please let me know what the r105 is, and what adjusting it will achieve? Thanks
Shadetree Mechanic
Delaware Base Station 808
Found it. R105 is the modulation adjustment on the clipper board. Is this the board that has been bypassed?
R105 is the modulation adjust on the clipper board and will have no effect since the board is bypassed.
If the receive audio doesn't fall off, than the audio/modulator circuit is ok because xmit and recv both use the same modulator.
I agree with your comment that the culprit is the modulation transformer. Maybe some turns in the secondary winding used for transmit are shorting as it warms up, and are lowering the modulation voltage. Check if the mod transformer is getting hot. this is my best guess w/o actually having it on my bench.
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If the receive audio doesn't fall off, than the audio/modulator circuit is ok because xmit and recv both use the same modulator.
I agree with your comment that the culprit is the modulation transformer. Maybe some turns in the secondary winding used for transmit are shorting as it warms up, and are lowering the modulation voltage. Check if the mod transformer is getting hot. this is my best guess w/o actually having it on my bench.
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Some new information that might help you to help me figure out if this is something I could possibly repair myself (although repairing it myself is unlikely.) Finding out what the issue is would be most excellent.
All my previous testing was done on channel 20.
I decided to test it every five Channel's up then down from 20.
As I get closer to channel 40 and then to 1 the DK is dropping down and by time I get to (Channel) 1 and 40 the output (dk) is zero.
Could it be the (6bq5) final causing the drop in modulated (pep) output?
I think I already know the answer.
I can replace the final but will not be able to neutralize it.
Will not being able to neutralize it be okay for a few minutes during the testing stage?
If I have to send it out for neutralization that's okay as I can have my technician go over the whole transceiver. I will have to look at it as if I'm sending it not only for a simple neutralization of the final, but a going over of the whole transceiver. I don't mind a little preventive medicine. Thanks for all your help.
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Yes. For future reference as to your 2340 that board has been removed. So the r105 in your 2340 should never have to come into play. Thanks for the help.
Shadetree Mechanic
Delaware Base Station 808
If it changes with the channel it makes me think about the SWR. What is your swr when you change the channels?
The SWR changes are negligible from Channel's 40 through 1. The SWR issues I have been experiencing isn't constant. I truly believe the install I performed of both pl259's on the LMR 400 that runs from my shack to the antenna was extremely poor. This is why I assume the SWR changes with the wheather. High winds, snow rain ect ect affect my swr. Even with the heavy falling snow my swr is currently a 1.5:1 (with 500 watts) that could change at any moment Until I remove both pl-259 and replace them correctly I will not use the station unless the SWR is below 2.
I worked with an SWR of 2 (or higher) for so long that once I saw a 1.1 I realized that even though that type of SWR isn't bad as far as possibly damaging equipment it's isn't good. One should always strive for an swr of 1.1 (or better.) I know this now. It's become priority number one for me. The chances of ruining a final with an SWR 2 isn't that likely, but since looking at the 1.1 I just can't bring myself to key the microphone when it's 2 (and sometimes higher.).
I am on the air right this moment listening to some local rag chew. I'm going take the time I have while the sonar is down to use the Madison. I'm also using it as a so long period to the rig. I have decided to sell it. As soon as my SWR, coax, and antenna situations are straightened out I'm going to purchase an ftdx 1200. The Madison has served me well over the last 3 years, but I want to move on to something that will allow me to listen to amateur radio bands. The fact that the ftdx 1200 makes for a far superior (SSB) "CB" radio also figures into my decision to sell the it. I'm waiting for a reply letting me know if replacing the 6bq5 final in the Sonar 2340 without neutralizing it in order to test it for about 15 minutes will be okay. I'm assuming that it'll be alright to install a new 6BQ5 final without neutralizing it. At least four the duration of a short test Period. If it indeed is okay to do so I will install one tomorrow. Either way it's going to have to be sent out to my technician. I don't have the test equipment nor the dexterity it takes to do the neutralization. As I mentioned in my previous reply I actually don't mind sending it out to him as he can go over it with a fine-tooth comb. Check out the capacitors, alignment, tubes etc etc. I will always operate the fs 2340 as my AM station. That's even after my ftdx 1200 purchase. That Yaesu will strictly be for SSB. STM. Thank you for Lending a hand. And in the meantime if you find out any other information about the issue I am having with the sonar please add it to this thread. Thank you my friend. It was and has been an excellent experience selling you the 2340. I not only enjoyed the selling experience I also made a friend while doing so. 73's for now. PS. This method of installing pl259's should never be used. It's quick, but my experience doing it this way has proven (at least to me) that one must drop solder through each of the three holes supplied on the pl259's braided wire access. That's why those holes are there. Imo installing pl259 connectors should never be done this way. And I let Bob the videos creator know this via a YouTube video clip response.
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Yes I am (using the antenna.) I discovered the audio dropping down while doing some local rag chewing (on the antenna obviously.) I would imagine there being no issue using the antenna (as opposed to the dummy load.) The swr is perfect while using the sonar @ 2 watts on the imax 2000. Is there a reason I should not use the antenna? I would guess I'm going to see negligible readings at 2 watts DK 12 pep whether I'm on the antenna or the dummy load. I switched over to the Madison. I put the the sonar and it's modulation issue on the side for now at least until I get a few more replies with some more information that might lead me to the problem. In all honesty I would like to to have an idea of what the problem is but in the end the radio will be sent out. I did what I could as far as changing the three tubes associated with the audio. Now that I've discovered the dkdrop to nothing on channels 1 and 40 I'm seriously thinking it could be the final causing the audio issue. If I can key up the microphone for a few seconds After changing the (6bq5) final without having to have the tube neutralized I will be able to see if the final is that's causing the issue. All i need to do is key the mic, say helloooo wait ten minutes then key again, give another helloooo, and if the audio stays at 12 pep the problem was the final 6bq5. If it drops down to 5 pep it's obviously not the final and something else. Weather it resolves the problem or not I will have to send it out anyway. Even if it's just to have the final neutralized (in the event the new final rectifies the problem.) And while it's there I will have mikM check out everything else that might be out of spec. The rig was fully restored about 3 years ago. Mike of did a superb restoration. Any of your advice and info is greatly appreciated. Thanks much. 73's
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Thank you for sharing the neutralization process via the link. The process is noted in my Sonar's manual. The problem is that my disability will not allow me to perform the neutralization. There are many things I will walk my xyl through but performing a neutralization is not one of them. She is the one who actually changed out the tubes for me. If someone lets me know whether or not I can operate the transceiver for 3 seconds with an unneutralized final I will go ahead and install it. I can then see if it is indeed the final that's causing the modulation issues. I am leaning towards the idea that it might be the final. The test in which I transmitted every 5 channels up and down from 20 (in witch my first testing was performed,) and found out the dk output drops as I go up twords 40 and down to 1, and then has absolutely no output carrier by time I reach channels 40, and 1. This is leading me to believe that the 6BQ5 final is soft (to say the least.) If I had to guess on my own I would say that transmitting and modulating for approximately 3 seconds in totality will not be or cause further issues if done with an unneutralized final. I would like to hear that from someone who is 100% positive that operating the transmitter with an unneutralized final is okay if just done for a few seconds. As I mentioned previously either way I am going to send the rig out. I would like to know what caused the audio issue and iif replacing the final and transmitting will show me whether it's the final or something else. If it is something else I am going to assume it's the modulation Transformer. Thanks again. And any further information or advice would be greatly appreciated. 73's ps. I actually recall a couple of people from back in the day who also operated transceivers that needed their finals neutralized when replaced who popped in a new Final without neutralizing it and operated their transceivers for the duration. If I recall they just didn't know how to do it or didn't believe it was necessary. In the short term I don't believe it affected their transceivers in anyway. Weather operating a transmitter with an unneutralize tube when it needs to be neutralized can adversely affect other parts of the transceiver in the long-term I would assume is possible. Their obviously is a reason final tubes need to be neutralized.
Shadetree Mechanic
Delaware Base Station 808
The manual says that neutralization may be necessary if V11 oscillates with no drive applied and the antenna disconnected. I don't know if there is an easy way to tell if it is oscillating. Part of the neutralizing procedure is with the unit keyed up. These are the only clues from the manual about wanting to swap the tube and try it.