Topics

PTT Intermittant

mikec@...
 

My TH-D700A is now on its 4th install location.  It's been in 3 different vehicles and now has been retired to shack duty.  It has developed an issue with the PTT.  When I key the mic, sometimes it transmits and sometimes it doesn't.  This doesn't seem to be the issue using the packet terminal though.  It transmits every time.  Has anyone had this problem before?  I'm curious if its a physical issue with the switch or its going brain dead.

Charles Blackburn <young_gun262001@...>
 

Most likely the switch.

 

Charlie

 

From: TMD700A@... [mailto:TMD700A@...]
Sent: Thursday, May 12, 2016 15:49
To: TMD700A@...
Subject: [TMD700A] PTT Intermittant

 



My TH-D700A is now on its 4th install location.  It's been in 3 different vehicles and now has been retired to shack duty.  It has developed an issue with the PTT.  When I key the mic, sometimes it transmits and sometimes it doesn't.  This doesn't seem to be the issue using the packet terminal though.  It transmits every time.  Has anyone had this problem before?  I'm curious if its a physical issue with the switch or its going brain dead.

 

Larry J. Ford K4AEC
 

Spray some Deox-It electronic cleaning solution into the PTT switch or carefully disassemble it, clean the contacts, apply some Deox-It as a final step before reassembly.

The PTT switch contacts may have developed some oxidation over time, or some foreign substance got in there, or both (or maybe just worn out).

If you know someone with a TM-D700A or another Kenwood that uses the same mic, try a different mic and see if you get the same problem.

Larry J. Ford
K4AEC
 





------ Original Message ------
Received: 03:50 PM EDT, 05/12/2016
From: "mikec@... [TMD700A]"
To:
Subject: [TMD700A] PTT Intermittant


Dennis Griffin <eagleeyedennis@...>
 

Many years ago, I replaced the keypads in two of that style Kenwood mic for a blind ham. My memory is a bit foggy on this, but I do recall that the face keys used a carbon like product on the back of the membrane for conductivity. I believe the PTT was a small, mechanically actuated switch soldered to a simple PC board in the back of the mic, so cleaning may be effective if that board were removed for isolated cleaning. The replaced parts were inexpensive, easy to obtain & easy to install.

73 de Dennis KD7CAC
Scottsdale, AZ

On May 12, 2016, at 12:49 PM, mikec@... [TMD700A] <TMD700A@...> wrote:

 

My TH-D700A is now on its 4th install location.  It's been in 3 different vehicles and now has been retired to shack duty.  It has developed an issue with the PTT.  When I key the mic, sometimes it transmits and sometimes it doesn't.  This doesn't seem to be the issue using the packet terminal though.  It transmits every time.  Has anyone had this problem before?  I'm curious if its a physical issue with the switch or its going brain dead.


Posted by: mikec@...

Randy Allen
 

I had a similar problem a few years ago with my TM731A, using the same mike (with a different connector, bought it aftermarket) as on the D700. IIRC The spring under the PTT button had sawed it's way through a cushion inside the mic. Bought replacement parts from Kenwood and no issues since then.

Can't find any of the documentation or related e-mails right now, but is something to look at if you determine the issue is with the mic.

73

Randy

On 5/12/2016 15:49, mikec@... [TMD700A] wrote:


My TH-D700A is now on its 4th install location. It's been in 3
different vehicles and now has been retired to shack duty. It has
developed an issue with the PTT. When I key the mic, sometimes it
transmits and sometimes it doesn't. This doesn't seem to be the issue
using the packet terminal though. It transmits every time. Has anyone
had this problem before? I'm curious if its a physical issue with the
switch or its going brain dead.

--
Randy Allen, KAØAZS