I like to err with the PTO range being slightly more than 1000 khz in ten turns, like 1000.5 khz, because it will age in the other direction and then be exact for a few years until it ages into less than 1000 khz in ten turns.
I only mess with it every 5 or 10 years but always give it a little extra. I learned this on the 51J-3 where the PTO range moved faster than kudzu weed. The R-390a pto doesn’t age as fast. Sent from Yahoo Mail for iPhone On Friday, November 8, 2024, 4:37 PM, Jordan Arndt <[email protected]> wrote: Ok...I have it adjusted so that the 000 endpoints are within <100hz, with a slight excursion to ~ 150hz off at the 500 mid-point. I need to find a stronger anti-b spring... 73...Jordan... ----- Original Message ----- From: "Jacques Fortin" <[email protected]> To: "'Jordan Arndt'" <[email protected]>; <[email protected]> Sent: Friday, November 08, 2024 3:03 PM Subject: RE: [R-390] PTO end point adjustment Sorry all, I believe that I got my Clockwise and Counter-clockwise moves in reverse... (again...) Can somebody confirm ?? In other words, what is the PTO output when the counter is at 7+000 MHz ?? 73, Jacques, VE2JFE in Montreal -----Message d'origine----- De : Jordan Arndt <[email protected]> Envoyé : 8 novembre 2024 16:25 À : Jacques Fortin <[email protected]>; [email protected] Objet : Re: [R-390] PTO end point adjustment Thanks Jacques... I've always done it without removing the PTO or the front panel...Now I have to find the tool I used to use...! 73...Jordan... ----- Original Message ----- From: "Jacques Fortin" <[email protected]> To: "'Jordan Arndt'" <[email protected]>; <[email protected]> Sent: Friday, November 08, 2024 1:03 PM Subject: RE: [R-390] PTO end point adjustment Hi Jordan, Y2K-R3, page 6-20 ! You zero-beat at 7+000 then goes down to 7.000 and adjust end point in PTO for zero beat. Up to 7+000 and re-zero beat with the BFO only. Back to 7.000 and re-zero beat with the end point, and loop again. Both ends sold be aligned after few iterations. But I neve aligned my PTO when they were IN the frame... I used an external supply, frequency counter and the alignment dial: Set PTO output to exactly 2.455MHz (almost fully clockwise) note the position on the alignment dial. Go back (counter-clockwise) exactly 10 turns to same alignment dial position. Set output to 3.455MHz exactly using the end point adjustment. Go up (clockwise) to 2.455 MHz exactly: expect dial reading change and take note of the new reading. Go back again 10 turns to this new dial reading. Set output again to 3.455MHz exactly using the end point adjustment. Loop again a couple of times: the two ends will converge to the same reading after few iterations. Once the end points give the same dial readings, re-install the PTO in the receiver with dial at 7+000 and PTO at 2.455 MHz positions. Check operation. 73, Jacques, VE2JFE in Montreal -----Message d'origine----- De : [email protected] <[email protected]> De la part de Jordan Arndt Envoyé : 8 novembre 2024 14:13 À : [email protected] Objet : [R-390] PTO end point adjustment It's been a long time since I had to adjust PTO end points and I need some advice as to the best method. Do I adjust the coil at the -000 end after setting the +000 end with the zero adjust or vice-versa..? Help...73...Jordan VE6ZT ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
