[1000mp] Mods for an Icy Day

[Bob Main]

Well since the weather is icy here in South Carolina today I decided to do the key-click mod on my Mark V.  First, if you hear me ever talk about working on the RF board again please schedule a mental evaluation for me.  After I got the board out and saw the underside I almost chickened out. Hans has a website that has some very good pictures about the steps to do both mods(http://www.remeeus.nl/english/hamradio/keyclick_nb_mod.htm) and was a BIG help, thanks Hans.  He was right about the PA unit when he said the tiny wires and getting the PA unit back in was a real pain.  Also I wish somebody would have mentioned the locking mechanism that the ribbon cables used.  I did not know about that, but once I learned the trick it was kinda neat to see how it worked.

I had planned to do the noise blanker mod too, but when I was listing the parts for the two mods my old brain listed the resistors as 22K, 680K and 220K (got carried away on the K's).  The NB mod requires a 220 ohm resistor, not 220K.  Luckily the one resistor that was incorrect was the NB mod so I was able to finish the key-click mod.  Which was good since I had just finished putting the RF board back on place and finishing up on that side.  Also the NB mod is rather easy to do and I won't have a problem with it when I get ready to do it.

In the near future I plan to get the roofing mod and the two 250Hz filters.  When they arrive I will do the NB mod when the bottom is off installing them.

Have not tested the mod yet, but I have plugged in the radio and turned it on.  No sparks or blown circuit breakers, yet, and I keyed the transmitter in SSB and CW and no smoke (again yet).

One other thing I wish I had had when doing this mod is a shorter iron.  One that is 10" long tends to shake at the tip end a bit to much.  (For some reason at 57 I'm not quite as steady as I used to be.)  Right as I made the last solder joint on the mod it shook and I touched one of the TINY resistors on the bottom of the board and actually "smeared" solder from one end to the other effectively shorting it out.  Luckily I saw it when I did it and got a de-soldering tool to pick up the extra solder.  I was also trying to be very careful not to get the resistor to hot.

73s
Bob
KB4CL