With a radio like that, you want to use the ALC line to the amp to limit the 
output so it doesn't over drive it and set it so it doesn't. As far as I 
know, the radio end of the amp relay is just that, nothing but a relay so it 
won't hurt the amp because the amp is what has the voltage coming off it you 
may have a bad amp relay though related to your output problems. Generally 
with tubes like the ones in that radio, the output will drop over time if 
they're going bad, it doesn't generally come and go or completely drop out 
though I suppose it could but it wouldn't come back if the tubes were bad. I 
think you have a relay problem somewhere, one is sticking, or not doing what 
it should for one reason or another.
----- Original Message ----- 
From: "Michael Ryan" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 26, 2015 8:06 AM
Subject: Keying a modern amp with a vintage transceiver


> Hi all: =20
>
> As modern rigs have problems keying an older amplifier, like a Heathkit =
> SB-220, Drake L-4 etc,=20
> with out the employment of a buffer box, can the opposite apply?=20
> Can a vintage transceiver, which most likely has much higher voltage to =
> key the older amps, put to much voltage into a modern amp's relay?=20
> Can damage occur to the transceiver if to much voltage is being used?=20
> I have a very sticky relay in my AL-811H and when it sticks, the RX =
> drops way down on the 102.=20
> The only way to restore the RX is to: 1, tap the amp on the cabinet =
> where the relay board is,=20
> 2, switch the amp into standby and back into operate or tap the PTT on =
> my desk mic or foot switch.=20
> I'm also concerned about over driving that may have caused some 
> damage.=20=
>
> My rig's SSB output uses the mic gain control to very the output.=20
> So even though I use CW to tune up things, switching to SSB probably =
> changes everything as the rig uses the mic gain to control the output on =
> SSB.=20
> My mic gain's position is about 9 o'clock and either barefoot or using =
> the amp, I don't change it.=20
> So its possible I'm over driving the amp on times. What kind of damage =
> can occur?=20
> On another note with the 102 it self:=20
> I'm still blowing a fuse every 3 months or so, about a total of 24 hours =
> of actual operating and I'm told that its my tubes.=20
> However, I don't see how as I'm still getting full output from the =
> tubes.=20
> If the tubes are indeed bad or on there way out, shouldn't I have =
> reduced output, getting lower and lower?=20
> Or when a tube goes, it goes at once from full output to half power 
> etc?=20=
>
>
> 73:=20
> Mike DE VO1AX =20