[Amps] AL-80A - Won't tune on 160m.

[Bill Coleman]

> On Sep 4, 2016, at 11:26 PM, Vic Rosenthal 4X6GP <k2vco.vic at gmail.com> wrote:
> 
> This is a common problem with this amp and the SB-1000 which is similar. You don't need to operate on 160m for this to happen. Here is an article which discusses the placement of a "corona washer" on the bandswitch to prevent this. Make sure you install such a washer when you fix the switch:
> 
> <http://www.northland-drifters.net/SB1000Project.htm>

Will do!

> The article also suggests replacing the parasitic suppressor with a different type. The original style parasitic suppressor is fine as long as the carbon resistor hasn't changed in value or even opened up. I would check this resistor and replace it if necessary. The nichrome type of suppressor isn't better and heats up more on 10 meters than the stock type.

Yes, I’ve read the debates on this. 

> Also while you are at it check the plate RF choke. There were several different chokes used in the manufacture of the AL80A and the early ones had a series resonance on 17m, which caused them to burn out if operated on that band. If the choke is one solid winding without gaps, replace it with an AL80B choke that you can get from Ameritron.

Uh. Yeah. I have no choice but to do this now… Part has been ordered.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901