Yaesu VX7R: Suddenly Almost No Ouput

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Yaakov

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Hello.

I have a VX7R which has suddenly decided to produce milliwatts of TX, regardless of the TX power setting.

It still transmits, and the audio is good, but the power is non-existent.

I haven't had a chance to put it on a meter to see just how puny it is, but it's as if the PA doesn't work.

Has anyone seen this?

Thanks!
 

mmckenna

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I've seen this happen with other radios. 10mw output was the last one that comes to mind. PA died, as you suspected.
 

Yaakov

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Thanks. I will probably just ship it to Yaesu. I don't feel like dealing with the tiny bits of the radio. I remember when you didn't need a Mantis to work on radios, and now even though I have one, I don't want to. Oh well.

Thinking about it, I might crack it open and see if it is something really obvious, though that seems unlikely...
 
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mmckenna

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Thanks. I will probably just ship it to Yaesu. I don't feel like dealing with the tiny bits of the radio. I remember when you didn't need a Mantis to work on radios, and now even though I have one, I don't want to. Oh well.

Thinking about it, I might crack it open and see if it is something really obvious, though that seems unlikely...

Yeah, it's pretty hard to actually "fix" todays radios unless you have the SMT tools. Yaesu won't be cheap, but they'll fix it. Get a quote first, and make sure it's worth the trip. My dad's FT-7800 failed and it was $150 to repair. Cheaper than a new one, but the same price as a single band 2 meter, which is all he really needed.

Good luck!
 

robertmac

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If this is on the ham bands, 6, 2, 220, 70 there is a problem. If using modified, there is the problem as well.
 

Yaakov

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robertmac:

I don't understand your comment. I am trying to transmit on 2m and 70cm with almost no output.
 

robertmac

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What I said was that if transmitting on ham frequencies and the measured output is lower than what is programmed, then there is a problem. Finals or something else. Many modify and illegally use these radios to transmit out of the ham bands. When doing so, the power output is often reduced as they are not intended to be used outside of the ham bands. As you say the problem is on the ham frequencies so the problem will have to be looked into more with meters.
 

wyShack

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a quick idea

You may wnat to check the antenna conection, particularly if you swap antennas fairly often. Not sure about the 7r but my 5R's bnc would twist j7ust enough over time that the center pin would pop loose. normally hard to tell on receive as it is 'hidden' by normally listening to strong local sigenals. The PA in most handhelds is fairly immune to high SWR -it either backs the output down or is designed to handle the mismatch as most 'duckies' are not much better.

it is a job to get in there but a touch of solder saved a trip to repair.

73
 

Yaakov

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wyShack:

Receive is 100%, so it can't be the antenna. I did swap antennas (the 7 uses SMA) because it was easy to try but the rig's antenna works fine on another handheld and the other antenna didn't help.

It would have been a nice thing, though, thanks for thinking of it! (I would have felt pretty silly if that's what the problem turned out to be.)
 

KE4PQG

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wyShack:

Receive is 100%, so it can't be the antenna. I did swap antennas (the 7 uses SMA) because it was easy to try but the rig's antenna works fine on another handheld and the other antenna didn't help.

It would have been a nice thing, though, thanks for thinking of it! (I would have felt pretty silly if that's what the problem turned out to be.)
I think wyShack is talking about the center pin of the BNC connector internal to the radio, where it is soldered to the circuit board, not the antenna itself..

Dave
 

w2txb

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Yaesu service is not cheap, but it is reasonable and they do good work. The only problem I ever had with them was when I had sent them a radio for repair, and they did not contact me with a quiote. After a few weeks, I called them and their person said they somehow missed calling me. At that point, they quoted the price for the repair, I approved it, and they got right on it. I received the radio within a week.
 

ZL2FAE

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I had that issue when the output stage cooked. I obtained a service manual and disassembled, located the board and ordered the replacement board as it was charred somewhat.
 
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