[Johnson] Courier amplifier

[Al Parker]

hi Bob,
	The Courier has tuned input I believe, so your high input SWR reading 
probably points to a problem in the tuned input ckt for bands higher 
than 75m.  Ck fir bad switch contacts, or burned capacitors.  If you 
have a way of measuring impedance vs freq., look at the input impedance 
on the bad bands, it should be in the 50 ohm range, and should be 
variable with the tuning cap.  If it resonates at a much higher freq. 
than the indicated band, then maybe a fixed cap is bad.
(I don't have a schematic at hand, so this is in general terms.)
73,

Al, W8UT
www.boatanchors.org
www.hammarlund.info

"There is nothing -- absolutely nothing -- half so much
worth doing as simply messing about in boats"
Ratty, to Mole

On 9/17/2016 12:40 PM, Robert Sauvan wrote:
>
> Hi all,
> I just got done refurbishing a Courier amplifier but I am having some
> loading issues with it. Im hoping someone has had a similar issue or
> some experience with these amps that can possibly give me some advice. I
> put a new transformer in it, along with all new electrolytics. It has
> 572B finals and 3B28 rectifier tubes. I am driving it with a Ranger II.
> What happens is this: I can load it up fine on 80 meters. Grid current
> is correct and adjustable. Power output is nearly 400 watts. On all
> other bands 40-10 meters I am only able to get 100 watts out if Im
> lucky. Grid current is very low. Supposed to be 60-80 ma but I only get
> maybe 20ma. I cant seem to get any more than that. I was also told to
> put my swr/power meter between the Ranger II and the Courier to see what
> I get there. On 80 meters, swr is fine at 1.5-1 or less. On 40-10 meters
> it is off the scale. Dont know what that means. Any suggestions/help in
> this would be greatly appreciated. The amplifier can be seen on my
> website- W0YBS.com
>
> Thanks-Bob-W0YBS
>