yaesu yd-844 microphone modification.
2m0-sil
it sounds superb on my ft-847 with very natural audio on ssb.
it also looks the part too.
the problem is very low audio on fm due to the high impedence of 50k ohm.
after having a look on the net i discovered an a-model of the mike with switchable impedence of 500 ohms and 50k ohms.
so my question is would it be easy enough to make this mike dual impedence.
thanks.
Brian Reay.
news:fdb7dda3-abd2-42b3...@glegroupsg2000goo.googlegroups.com...
I think your problem is really that you need a 500 ohm mic and have a 50k
one, you wouldn't normally change the impedance as you changed mode. A
couple of options spring to mind. A transformer or a buffer amplifier, with
a high Z input and a lo-Z output.
I've just looked on the web and Yaesu used a transformer. Maplin do one,
but is it "cased"
http://www.maplin.co.uk/microphone-transformer-xlr-to-1-4-mono-plug-12151
Not cheap and you'd have to extract the transformer and mount it in the 844
case.
You can probably get a transformer elsewhere, you need a 100:1
transformation. Such things are common enough in the audio world so a bit
of digging should find something and probably for less that the Maplin
offering. However, it may come down to convenience.
An electronic solution is the other option, perhaps as simple as an emitter
follower may do it, if the current input is dragging the mic output down due
to the source impedance. I'd recommend the transformer approach, why
re-invent the wheel.
These days, unless you've some older radios about, I'm not sure I'd worry
about having it dual impedance. The 844 seems to be FT101 vintage.
--
73
Brian G8OSN/W8OSN
www.g8osn.net
2m0-sil
not as straightforward as i had hoped but oh well.
shame really but the mike will stay as i love the retro lines and they certainly knew how to put mikes together back in the day.
im going to put together a ptt box for my md-1.
i purchased the microphone but not the main body and i dont think the little on-off switch on the mike will stand up to repeated use so a seperate ptt box is in order.
Jeff
Mode should have no implications on mic performance, if there is a
problem on FM them there will be a problem on SSB (unless you are
talking about using it on a different radio).
What radio are you trying to use this mic on?
Jeff
GM4DHJ/M....
go up to RME in howard street and buy 50k hand mics and throw away the
transformers......
2m0-sil
good reports on ssb--but low audio on fm.
joe jbn
RADIO IS FT-847 EARTH STATION , YES I HAVE HEARD THE MIC IN QUESTION ,
THE SSB AUDIO IS MINTED BUT ON FM IT'S RATHER LOW OUT , STILL NATURAL
SOUNDING BUT REALLY LOW VOLUME WISE
Jeff
> its a yaesu ft 847 jeff.
> good reports on ssb--but low audio on fm.
It seems unlikely that you can have sufficient mic gain for full output
on ssb, but too little on FM. Does that radio have separate settings for
mic gain on ssb and ssb?
Jeff
Jeff
>> Jeff
>
> RADIO IS FT-847 EARTH STATION ,
What is an "EARTH STATION"?
YES I HAVE HEARD THE MIC IN QUESTION ,
> THE SSB AUDIO IS MINTED
and what does "MINTED" mean? (rounded but with a hole some where perhaps)
Jeff
2m0-sil
when replaced by the stock mike everythings fine.
minted is glaswegian for excellent jeff.
Jeff
A very quick look on the web shows that Menu 25, FM-p-set, controls the
FM mic gain. (page 86 in the manual)
Jeff
2m0-sil
will try that-thanks again jeff.
GM4DHJ/M....
> lol--just shows how long its been since i looked at the manual.
> will try that-thanks again jeff.
ha ha .......
2m0-sil
have you never had a senior moment jimbo.
Satans Rat
So what you are in fact suggesting is that your
rigs mic input impedance changes depending upon
operating mode.
Pillock !
joe jbn
like my good comrad suggested the minted part means most excellent and
earth station , means THAT'S WIT IT SAYS ON THE BOX they call them
earth stations because it does sat-alight communication.....DOPPLER
SHIFT 2VFOS UHF UP AND VHF DOWN ECT ECT ECT.......
joe jbn
> lol--just shows how long its been since i looked at the manual.
> will try that-thanks again jeff.
JIMBO YOU HAVE THE RIGHT TO GET TORE INTO HIM..........
2m0-sil
2m0-sil
carrier of vermin.
jim stewart
"joe jbn" <jbre...@gmail.com> wrote in message
news:bba9d5ec-527a-4547...@t29g2000vby.googlegroups.com...
what with him a trainer as well ? .........wouldn't dare......anyway I never
read manuals myself .....
2m0-sil
jim stewart
> good shout jimbo.
minted ma man.....
mm6jbn/p
wrote:
> "joe jbn" <jbree...@gmail.com> wrote in message