[R-390] replacement R390A gear clamp source

[Jordan Arndt]

Paul....

Seeing that you have a Cosmos PTO, there are 2 seperate adjustments. One 
sets the end to end 1Mc ten turn coverage, and another that sets the 25kc 
points which is much more involved and difficult to adjust.

You should do some reading about the Cosmos adjustments...

73...Jordan VE6ZT

----- Original Message ----- 
From: "Paul Roche" <rochep at comcast.net>
To: "Jordan Arndt" <Outposter30 at shaw.ca>
Cc: "Barry" <n4buq at knology.net>; "R-390 Mailing List" 
<r-390 at mailman.qth.net>
Sent: Saturday, July 25, 2026 9:45 AM
Subject: Re: [R-390] replacement R390A gear clamp source


It is a Cosmos 136-1 PTO, SN 21195 (I think that’s means it’s a pretty late 
one).
Sent from my iPhone

> On Jul 25, 2026, at 11:23 AM, Jordan Arndt <Outposter30 at shaw.ca> wrote:
>
> Paul....What you're seeeing is the cover for the adjustment....the real 
> adjustemnt is hidden behind that cover screw which you need to remove. 
> Behind it is a small slotted brass rod that you adjust...I wouldn't try to 
> adjust it until you're sure you have everything properly synchronized.
>
> What type of PTO is it...? Collins type or Cosmos type...?
>
> YMMV....73...Jordan VE6ZT