I have a Yaesu VX-5R HT, and it works just fine. The built-in condenser mike sounds transmits a clear voice (according to listeners). The problem is that when I attach the speaker mic (Yaesu MH-34) which is prescribed for it, I have problems. The speaker portion of the mic works fine. It's the mic capability that's in question.
When I talk to about 50% of the local repeaters, they say my voice is very, very muffled, like "in a box" when I use the speaker mic. When I use the rig's built-in mic. They say I sound clear. Here's the kicker... on some different repeaters, I'm told the speaker mic transmit audio quality is fine. And simplex transmissions are fine. It's just that with some repeaters, the mic portion of my speaker mic sounds lousy and muffled, but with other repeaters or simplex, it sounds fine. The HT's built-in mic sound fine no matter what repeaters I use, or if I do simplex. (This is all on 2meter, by the way).
So, last night, I did an experiment where I had another ham operate my HT while I did his. He used the speaker mic on mine and transmitted to a local repeater. Sure enough, what I heard sounded lousy. We then proceeded to go simplex, and then the speaker mic sounded perfect... no problems.
My question is why will SOME repeaters see my speaker mic audio as lousy but my built-in mic sound great... and why do other repeaters not show this problem? It's really about half the local repeaters, so it's an annoying problem. Is it the speaker mic? I guess, probably, since the built-in mic is fine. But why on some frequencies? Is the mic defective? I don't know... how come it worked fine in simplex? The mic is made to work with this HT (this is the speaker mic Yaesu sells for this HT). The specs show them to be compatible. Is there a speaker mic that won't exhibit these problems?
As an extra note, I was chatting with a dealer for that speaker mic who took a guess that the bandwidth of the mic may be wider than what many repeaters allow ( many repeaters narrow what they receive). And the internal mic on the HT may not be as wide which is why it's sounds good through the repeater. He thought perhaps adding a capacitor to the speaker mic to narrow the bandwidth may help (or hinder). Any ideas or details about this?
Any ideas in general what is going on with what I described earlier in the post? Does anyone else have similar problems?
Along with your response post to this forum, if you could e-mail me your response directly as well, that would be great. If not, a forum response is just fine.
Thanks in advance to anyone that can help!
Steve Rifkin
steve410@erols.comKA3ZMN