[1000mp] Keyer question on Mark V Field

[Bruno Tréguier]

Mike Schatzberg wrote:
> Hello Bruno:
> 
> Check the mode your MkV keyer is working in, and change it to the other one,
> and see if the problem persists.
> 
> Seems to me there can be a bug in one of the two working modes.
> 
> Let me know what happens, thanks,

Hello Mike and everybody,

Ok, I'm coming back after a few tests during the last weeks. Here is 
what I experienced:

First of all, I bought another key from a local ham here, it's a nice 
Schurr Profi 2. So I now have this one and my MFJ-564.

As suggested by Mike, I tested the second mode (Iambic 2, as my 
transceiver was in Iambic 1), and the problems were the same. But...

It seemed to me that the situation was a bit better with my new Schurr 
key, except for 1 evening, just after I had cleaned the key I had just 
acquired, with water, soap, and a toothbrush. What was happening then 
was an "amplified" version of the phenomenon: no problem with the "dash" 
paddle, but as soon as I pressed the "dot" paddle, the keyer would not 
stop keying and would send tons of dots. No way to stop that, except by 
simply disconnecting the key, and re-plugging it in. I quickly realised 
what the problem was: I hadn't correctly dried my key and the connector 
contacts, under the key, were still a bit humid (not even wet !). So I 
took a hair drier and corrected this. I had no more problems after that !

My conclusion is that my FT-1000 MP Mark V Field is VERY sensitive 
regarding the key connection, and that a slight insulation problem can 
cause this kind of odd behaviour. So I guess that my MFJ key has an 
insulation problem somewhere, that I'll have to correct.

If I have some time I'll check what's the minimum resistance making the 
transceiver consider that the contact is closed on the dot side, and 
I'll keep you informed. I've already had a look at the schematics, and 
it seems the 2 lines (dash and dot) are connected to Q5035 (which is the 
keyer CPU) and that there are 2 pull-up resistors whose value is 47K (so 
I guess the value of the minimum resistance must be around the same value).

Best regards to you all,

Bruno