TX audio low on FT-270R

[AD7TI]

I have this Yaesu FT-270R waterproof HT that I really like except for one problem. The TX audio is low to the point of being unusable. To make matters even more annoying, sometimes the TX audio is almost acceptable but then a few days later it is like talking to a brick again. I haven't done any scientific correlation studies or anything but it almost seems to change with the weather. Excluding some of the Chinese made bargain radios, Yaesu makes other waterproof radios as well as other manufacturers all of which don't seem to have this problem. One solution is to always use a speaker/mic with the HT, but I would like to fix the root problem. Two solutions that I have seen searching the internet are to remove the waterproof diaphragm over the mic and increase the signal deviation. Removing the diaphragm kinda defeats the purpose for having a waterproof radio and I would rather not muck with the transmission characteristics.


Does anyone have any words of wisdom regarding this?

[AC0VH]

I had half deviation set on some of my memories which causes low audio. I've never found it necessary to adjust the deviation in the service menu once I figured out that low audio issue.

However from your description it's probably the waterproofing. This is very common with the VX-7R I have and I guess other radios, too. Yaesu put a membrane over the mic and actually when you mention changes in weather that makes it even more likely. When the barometric pressure changes the membrane sometimes puffs out a little bit with low pressure, just like driving up and down in elevation and a potato chip bag.

I poked a pin hole in the membrane and it solves this problem. Yup, technically this makes it no longer totally waterproof, but it's no more leaky than the SMA/BNC adapter I put on it or the speaker/mic plug cap. The radio is really only immersion proof, not water proof, and the pin hole isn't going to let much water by over a second or two in water. Besides, having a vent probably keeps condensation from forming inside anyway.

[AG3NT]

Echoing the above, this is extremely common on all of Yaesu's "submersible' models. I've experienced it on at least four of their products so far... VX-7R, the speaker-mic for the VX-7R (which is submersible rated), the Standard Horizon HX370S 2m HT, and the waterproof speaker for the FTM-350AR.

The membrane is supposedly Gore-Tex material, which should eliminate moisture/condensation issues though. But yeah, that's just the way it is with the submersible products. I've stood in torrential downpours with the HX370S and the submersible mic though, and had no issues relating to water getting in. In cases where you NEED the waterproof nature of the products, it's invaluable. Other times, I just use a cheaper Pryme speaker mic to avoid the issue.

[AD7TI]

Yea, I was taking a bit of literary license with the waterproof comment. Dust is really more of a concern than water. I figured if it can tolerate being dunked in water then it should also be more or less dust resistant. I like the pinhole idea. Maybe waiting for the radio to get good and deaf then popping off the battery and let it breath of a bit, Then test it again to see if there is a difference. Otherwise, it's back to the speaker mic. Thanks for the input.