GONSET G77 TX SLOW KEY UP

[WB6SLC]

We rebuilt a G77 and the vibe was dead as usual; so W6WTU engineered up a FET multivibrator that is fast turn-on & runs cool. Replaced all supply caps & tubes, got it up running BUT!
The first PTT relay keys up instantly when you press the button but when that keys it starts up the multivibrator which is near instant with the HV coming up in a few milliseconds but the second keying relay that actually starts the TX power to flow is WAY slow at about 1000 ms later....very annoying! Impossible to "break in" or get back to someone and forget contesting! Question is that since it didn't work on arrival, caps & tubes were shot we were never able to get to find out if this is "a design bug" present in all of them OR did we miss fixing another "known bug" of some kind? Any owners of G77 please get back to me & let me know if YOURS does the same thing "factory stock". Reply to WB6SLC at ARRL.net or to here is OK too.

[WD5JKO]

I run a G-76, so the G-77 is a very different thing. I looked at the G-77 schematic at Bama, and it appears there is a step-start key-up. This is to preserve the vibrator contacts.

Look at the schematic, and on the secondary of T1 is R217, a 330 ohm 2W resistor. When you key up, this resistor is present. Later when Rel-2 kicks in, the resistor R217 is shorted out.

I would look at R217 to see if it has drifted up in value. Also look at R216, a 22K 2W in series with Rel-2 coil. Maybe it went up as well.

When you re-capped the rig, if you went up in value with the filter caps (125 uf @ 350v), then the turn on delay will lengthen.

73,
Jim
Wd5JKO

[WB6SLC]

My buddy W6WTU Hugh Wells is doing the rework for me; he pretty much threw in the towel on the delay issue until I told him I would put it on the AMFONE list; he then rapidly agreed to change the value of the resistor(s) to see if that would cure it. He took the G66 and G77 back from "the dead" to really working quite well....so I have nothing to complain about! Please contact me off the group with your email info so I can connect you & Hugh together. WB6SLC@ARRL.net should work.