Re: {Collins} KWM2 grid problem help?

Hi Steve,

just saw your post and have an idea.

I suggest you first of all remove the cinch connection between KWM-2 and
30L-1, going from "ALC" to "ALC" (the connection is there, right?). Then
run the M-2 barefoot through the L-1 into a dummy load and confirm it's
working properly.

Then you should know a few simple things:
1. in USB or LSB mode and everything running properly the ALC will work
to suppress any grid current. You simply won't see any grid current, but
you can see ALC meter indication.
2. in LOCK and TUNE the ALC is defeated. Now you won't see any ALC meter
indication but you can see grid current and use it for tuning.
3. the ALC meter indication is notorious for zero reference wandering
around. Try to set it like this: LSB/USB mode, PTT on, MIC GAIN off, set
ALC meter indication to zero. The pot is under the lid, second from
left. Don't overdo that, it's not precision measuring equipment. In
normal operation you just want to see the ALC indicator jump around
according to what you put into the mic.

Now - switch the 30L-1 on again and confirm you get your 600W or so in
LOCK mode. Back to USB/LSB mode, turn MIC GAIN up and whistle: full output?
Then - reconnect the ALC-ALC cable: low output again?

All that said and done, I suspect the ALC circuit in the 30L-1 is
defective, sending some negative ALC signal to the M-2 and thereby
reducing its output when driving the L-1.

Hope that helps,
Ernst DJ7HS
CCA AC09-12284

Am 14.05.2019 um 18:35 schrieb Steve:
Hi all,

I have a Winged emblem kwm2 and a winged 30L1.

When I am transmitting through the 30L1  the output is weak and the grid
current is zero.

The ALC will peg out if I move the mic gain up too far but still the
grid is zero.
When I transmit without the 30L1 the grid current will sit around 250
with the mic gain at 25%.

The output from the kwm2 is 90+ when I whistle in the mic without the
30L1. But with the amp I can only get about 250W.

Key down in "lock" mode the kwm2 and 30L1 will go to 600W but still no
grid current

once again the ALC will show pegged if I turn the mic gain above 25%

Also when I am in lock mode the grid current will slowly bleed off over
10 seconds with the 30L1 transmitting.

It does not do this without the amp.  grid current is much more stable.
It does bleed off a little but very slow.

Help? or is this normal.


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