Yaesu: Mic Button - FT8900

[KK4JUG]

The mic button on my Yaesu FT8900 is extremely sensitive. It's very difficult to handle the mic without keying the transmitter. It's the MH-48 mic. I'm willing to take the mic apart if I know I can make some kind of adjustment. Is it worth the effort?

 

[AK9R]

I've never had one of those apart, so this is just speculation. See if you can figure out how the spring behind the PTT works. It may be a small torsion spring like this:

https://www.zoro.com/value-brand-to...m3kNdaRzOI9DHfb_bR9NSGSF0zs6YXnbmQaAhVN8P8HAQ

or a flat blade leaf spring. Either way, you may be able to shim the spring a bit to increase the tension on the button.

 

[jim202]

The mic button on my Yaesu FT8900 is extremely sensitive. It's very difficult to handle the mic without keying the transmitter. It's the MH-48 mic. I'm willing to take the mic apart if I know I can make some kind of adjustment. Is it worth the effort?

I would hesitate opening up the mic until you have exhausted all means to get the company to resolve the problem for you.

The solution to the sensitive mic switch will depend on just how it is constructed. Most of the switches used today are sealed micro switches. There is no adjustment. However, if the mic does come apart, I would look to see if it is possible to move the switch just a fraction away from the mic button.

A second approach might be to contact the company and see what they say. You might get a new mic sent to you if this is a recent purchase. If you bought it from a local or mail order place, try talking with them and see what they come up with.

 

[kb5udf]

Try tightening external screws

I once had, I believe the same mic, with the opposite problem, too hard to key. It seemed like
the plastic mic case was overly tightened, so I gently loosened the screws. You may
have luck doing the opposite.

Regards

JB

 

[KK4JUG]

Thanks, guys. kb5udf, the case appears to be OK. The mic button moves quite freely. I simply want to increase the distance the button has to travel before engaging the switch. I don't think loosening the screws would help.

I'll try to contact the dealer and or Yaesu. I have a Kenwood mic with the same type of mic (same buttons, different configuration). I know it's a long shot but would that work as a substitute until I get the Yaesu problem fixed?

 

[apx7000xe]

I have the same problem with a Kenwood tk-2180


Kenwood TK-2180 | Motorola HT1550•XLS | Motorola HT1250 | Motorola CP200XLS | Kenwood TK-790 | Motorola Minitor VI

 

[KC4RAF]

The MH-48 that goes to my FT-2900 is the same as yours'. The slightest touch and it keys up the radio. Was going to open the mic up, but the doctors decided to open me up instead!
I just got to the point of being very careful, but that isn't that easy to do.

 

[KK4JUG]

This appears to be a relatively common problem. When and if I come across a solution, I'll be sure to post it here.

 

[KC4RAF]

KK4JUG, just got mine opened and solved the problem.
On the lever that you push, you'll see an angled nipple that touches the micro switch lever. What I did was used some 100 grit sandpaper and decreased the length by about 1/32 to 3/64 of an inch. I first used a scalpel to mark that nipple so I would have an idea how much I was removing.
Opening the mic up isn't too bad, the hardest was keeping the PTT lever in the hole. You'll see what I mean.
hth.

edit: just did a test and it improved greatly!!!

 

[KK4JUG]

Great! Thanks. I'll try it.

You beat me to it. We've had thunderstorms here all afternoon and I was waiting for the lightning and thunder to move on.

 

[hill]

I would like this mic to be more robust, since the one fell apart on my FT8800 in the car, but did last about 7 years and the one on the FT2900 in the work truck isn't far behind. Both have had the mic cords come apart, but the one I just replaced in the car even the ptt was falling out.

 

[KK4JUG]

You make a great point. It seems that the mic is the flimsiest part of the radio but it's the one item that gets dropped, bounced around, etc. A "ruggedized" mic might be a great selling point. Right now, the only selling point is whether it does tones.

 

[kayn1n32008]

I would like this mic to be more robust, since the one fell apart on my FT8800 in the car, but did last about 7 years and the one on the FT2900 in the work truck isn't far behind. Both have had the mic cords come apart, but the one I just replaced in the car even the ptt was falling out.

The MH45 or whatever it's called feels cheap. It has no weight to it.

I do not miss that crappy mic. The Kenwood radio I have now has a much better built microphone. I have had some issues with it. It stopped consistently keying the radio for a while. Has not happened in about a year. I did trade the hammy cable that came with is with a LMR cable at work, because the LMR cables have a rubber boot on the end that plugs into the radio. The hammy cable does not.

Sent from my SM-G870W using Tapatalk

 

[KK4JUG]

KC4RAF, I tried your technique and it worked great. Actually, I took just a hair too much off the switch so I simply bent the lever on the micro switch just enough to bring it back to life. The whole thing didn't take more that 4 or 5 minutes and, like you said, it was easy.

Thanks for the help.

 

[KC4RAF]

Glad it worked out for you KK4JUG. It bothered me ever since I had the 2900, just a slight touch on the PPT lever and it would transmit. I'm glad you posted about it the other day.
Yeah, that little bit of removal of plastic solved the problem, and as you posted, if too much removed, just bend the metal lever out and it works great...