I have a Mic. problem. FT-100-D

[K6TC]

This new rig will not un-Key on FM only...works fine on all HF-UHF bands...what gives?? anyone know???
K6TC wondering

[KD7EZE]

If it is new as you state, just send it back for replacement.

[WA6BFH]

The first thought is -- mode has nothing to do with wavelength bands! So, are you saying -- on FM -- a carrier mode -- the radio is keyed but, is it also keyed on SSB? Obviously there will be no carrier but, is the transmitter keyed?

The next point of attack,

1) Is it a DC problem, like is the PTT line shorted?

2) Is the VOX turned on?

3) Is it a software glitch that re-setting would fix?

[N6AJR]

do you have VOX on

[KC8VWM]

Thoughts to think about:

There is a menu feature in the radio that may be causing the problem?

The DTMF micrphone for the FT-100 is designed to function ONLY when the radio is placed in the FM mode. Therefore, If a DTMF key was shorted out or in a constant state of "on", it would only be noticed when the radio mode switch is placed in FM mode. Also the FT-100 does not give any audio feedback to the user when pressing DTMF tones, so you may be completely unaware it is occuring.

Pressing the DTMF pad while operating HF or other modes will have no effect.

Crossband operation.

Perhaps a setting in the crossband feature of the radio is causing the radio to transmit? What happens when you adjust the squelch, RF gain or other reciever settings.. does the carrier drop?

Radio mods?

Some previous internal radio mods have shorted out causing the radio to TX?

The FT100 has a known UHF/VHF thermal sensor mod that affects V/U receive mode fans. Has the thermal sensor mod failed or shorted out with the circuit board causing it to TX?

See photos of Mod here: - http://www.k0lee.com/thermalmod.htm

ATAS100 autotuner feature:

The FT100 and FT847 has autotuning functionality. Menu item 61 is has several settings for controlling the way the ATAS100 antenna works including VHF/UHF operation. Is the radio stuck in TX mode because it is looking for the ATAS antenna to tune up?

Is the autotune feature enabled for VHF/UHF bands only?

Any other ideas out there?

73 Charles - KC8VWM

[N6AJR]

try a master reset??

[WT0A]

TX button pushed?

[NA9Q]

I have seen this in several newer radios and it relates to a DC input supply voltage sensitivity issue.  Since FM mode is a full duty cycle mode (even at a reduced carrier), as soon as the mic is keyed the DC current drain increases to a high steady value.  If the supply voltage sags significanly under this heavier current drain, some of the newer radios will lock on in transmit mode. Only disconnecting it will turn it off. Typically you don't see this in SSB mode as there is only a small increase in DC current when the mic is keyed, unless of course you have a high average content audio input to the mic (like a steady whistle).

I saw this in my FT100D when it was new when, just for initial testing, I tried to run it from a cigarette lighter outlet.  As soon as I keyed it on FM, it locked on and had to be disconnected before it would shut down.  I saw this also on a friends' ICOM 50W FM radio when the engine was off and the DC voltage was at its' lowest.  My own IC207H will do it in the high power mode as well if the engine is off and the battery is low.  If you read the manuals of many of the newer FM 50W and higher radios, the manufacturers caution against transmitting (especially in high power mode) with the engine off.

I hope this helps...

73, Mike, NA9Q

[K6TC]

This was the solution to my problem folks...this gentleman was the help I needed to correct my problem. By his personal experience I was able to disconnect the main power lead and reconnect then go through the menu to bring up the memory channels and all was back to normal. What a relief!!! I was ready with credit card in hand to start buying parts from Yaesu until I came upon what ever it took to correct what had gone bad in this VERY expensive rig I use only for my mobil HF-VHF work while on the road. My thanks go out to Mike and his wife for their help.
May I be offered a chance one day to be able to repay them in kind
73 de Tom es Rocky K6TC-K6RGC
Lakeside, Oregon***