Heathkit SB-200 80 meter tuning issue

[Crambone]

when I try to tune up on 80 meters the following occurs all other Bands seen fine.
Input 30 watts, when I key up and go to tune I get some upward grid current but it slowly drops not allowing me to tune. I’m seeing 2300 volts and Grid and Plate current. Any suggestions where I might begin to look?

73’s KB2LMN

 

[wavrider]

door knob cap for 80 meters in the PIL output tank circuit, they get old and go out of tolerance.
As you are looking down on the tank circuit should be on right hand side, there is also one for 40 meters.

What is the input vswr on 80 meters??

 

[nomadradio]

Hopefully no burned contact points on the band switch.

73

 

[Crambone]

I replace both door knob caps prior as they were way out. I will take a closer look at the contacts.

 

[Crambone]

door knob cap for 80 meters in the PIL output tank circuit, they get old and go out of tolerance.
As you are looking down on the tank circuit should be on right hand side, there is also one for 40 meters.

What is the input vswr on 80 meters??

I’m going to check the input vswr I can’t recall

 

[wavrider]

ok and visually inspect the band selector switch for any corrosion , the input and output switch is a weak point on Heathkit amps, some de oxit and clean it with acid brush seems to clean contacts decent.
the input and output circuit can be troubleshot by using an vtvm checking for continuity.
I don't check in to the forum often work keeping me busy so good luck on the old sb200 they are good table top amps, have a few here.
Harbach is where I get my replacement parts but someone posted Steve's basement got flooded out.

 

[Crambone]

ok and visually inspect the band selector switch for any corrosion , the input and output switch is a weak point on Heathkit amps, some de oxit and clean it with acid brush seems to clean contacts decent.
the input and output circuit can be troubleshot by using an vtvm checking for continuity.
I don't check in to the forum often work keeping me busy so good luck on the old sb200 they are good table top amps, have a few here.
Harbach is where I get my replacement parts but someone posted Steve's basement got flooded out.

Input tune is out I’m getting a 4+. Cleaned all the switches and contacts. Going to tune input tomorrow if I get a chance.

 

[wavrider]

https://pa0fri.home.xs4all.nl/Lineairs/SB200/sb200eng.htm

many years ago I used this site and had a lot of fun doing the mods to an ols sb200,, I still have that same 200 with the cetron tubes in it full output..you will get the old sb200 up and running soon

 

[Crambone]

https://pa0fri.home.xs4all.nl/Lineairs/SB200/sb200eng.htm

many years ago I used this site and had a lot of fun doing the mods to an ols sb200,, I still have that same 200 with the cetron tubes in it full output..you will get the old sb200 up and running soon

Great site thanks!

 

[wavrider]

any update on the old heathkit??