Hi AFIK, Motorola never made PTO’s for anybody else. They had “way too much fun” just making them for their own production radios.
Based on chat’s with the folks at Collins, everything that went into their radios came out of their factory. They obviously sourced many (but not all …) components. All the assemblies got done “in house”. Bob > On Sep 18, 2024, at 10:15 AM, Les Locklear <[email protected]> wrote: > > Yes, Whoever manufactured the R-390/URR's, (Collins and Motorola) The PTO's > were labeled individually. Many are missing the labels these days... > Les > > > ----- Original Message ----- > From: Barry <[email protected]> > To: Les Locklear <[email protected]> > Cc: Bob kb8tq <[email protected]>, R-390 Mailing List <[email protected]>, > Larry Haney <[email protected]> > Sent: 9/18/2024 9:05:21 AM > Subject: Re: [R-390] R-390 VFO Question > ________________________________________________________________________________ > >> For the R-390/URR, are they labeled as Collins or Motorola? In other words, >> did Collins rebrand the Motorola PTOs or leave them branded as Motorola? >> Just curious so I know who made mine. Its label shows "Collins Radio >> Company". >> Thanks, >> Barry - N4BUQ >>> On the R390/URR Collins and Motorola made PTO's. >>> On the R-390A/URR Collins, Progressitron, Dubrow, Motorola and Cosmos. >>> There are >>> quite a few out there with Raytheon labels, but they were rebuilt under a >>> separate contract. >>> Les >>> ----- Original Message ----- >>> From: Bob Camp <[email protected]> >>> To: Barry <[email protected]> >>> Cc: R-390 Mailing List <[email protected]>, Larry Haney >>> <[email protected]> >>> Sent: 9/18/2024 7:20:55 AM >>> Subject: Re: [R-390] R-390 VFO Question >>> ________________________________________________________________________________ >>>> Hi >>>> Motorola most certainly made their own PTO’s for the radios they supplied. >>>> Long >>>> ago I talked to the folks who did the linearity adjustments on them. They >>>> still >>>> had (not so) fond memories of doing those adjustments. >>>> Bob >>>>> On Sep 17, 2024, at 11:29 PM, Barry <[email protected]> wrote: >>>>> Hi Larry, >>>>> Regarding the tutorials, I'm wondering which might apply to the PTO in the >>>>> R-390A/URR. I see most(all?) of them are regarding the COSMOS units but >>>>> am >>>>> wondering which PTO is in the R-390/URR and whether any of the >>>>> rebuild/linearity documents apply to that one. Were all the R-390/URR >>>>> PTOs >>>>> made by Collins and no COSMOS in that version? >>>>> Mine is running just a bit fat - maybe 1.5 kc end-to-end. I have the >>>>> actual >>>>> numbers written down and can post that when I get back to the workbench. >>>>> From >>>>> what I remember, removing a turn shortens the end-to-end but perhaps >>>>> additional >>>>> C would work as well. I >>>>> don't know what effect that might have on linearity but I don't think it >>>>> should. >>>>> The R-390A/URR PTO has an endpoint adjustment. Does this exist for the >>>>> PTO >>>>> in an R-390/URR? >>>>> Thanks, >>>>> Barry - N4BUQ >>>>>> Hi Barry, I thought what you wrote makes sense and is correct. It's >>>>>> good >>>>>> that you are understanding how it all works. It makes diagnosys so much >>>>>> easier. Good going. >>>>>> If you're interested in more reading on the 390A PTO's, there are 3 docs >>>>>> on >>>>>> our website in the repair tutorials section by Tom Marcotte, Jim Miller >>>>>> and >>>>>> myself. >>>>>> Regards, Larry >>>>>> On Mon, Sep 16, 2024 at 5:51 AM Barry Scott <[email protected]> >>>>>> wrote: >>>>>>> Okay, Larry. Thanks for the reply. >>>>>>> On further reading, the VFO is a Hartley design and, given that the >>>>>>> frequency formula for a Hartley is an inverse function of the LC values, >>>>>>> presuming that at xx 000, the iron core is "out" of the coil and a >>>>>>> clockwise turn of the KC knob causes the core to be pushed further >>>>>>> inside >>>>>>> the coil increasing the L, then the frequency would indeed drop with CW >>>>>>> motion of the knob. Sorry for the awkward way of stating that but I >>>>>>> think >>>>>>> it makes sense to me. >>>>>>> Thanks again, >>>>>>> Barry - N4BUQ >>>>>>> Thanks, >>>>>>> Barry - N4BUQ >>>>>>> On Sun, Sep 15, 2024 at 11:10 PM Larry Haney <[email protected]> >>>>>>> wrote: >>>>>>>> Hi Barry, You are absolutely correct in your deductions. When the KC >>>>>>>> is >>>>>>>> at its lowest of 000, the vfo is at its highest (3.455 mh). >>>>>>>> Regards, Larry >>>>>>>> On Sun, Sep 15, 2024 at 7:23 PM Barry Scott <[email protected]> >>>>>>>> wrote: >>>>>>>>> Looking at the simplified schematic for the 3rd mixer (V205), the >>>>>>>>> output >>>>>>>>> from the 2nd mixer (V204) tunes from 3 to 2 MC and the VFO tunes from >>>>>>>>> 3.455 >>>>>>>>> MC to 2.455 MC yielding a constant 455 kc mixer product. Is it >>>>>>>>> correct >>>>>>> to >>>>>>>>> interpret those numbers to mean that if the counter starts at XX 000 >>>>>>> and >>>>>>>>> the KC control is rotated CW to XX +000 the VFO's output frequency >>>>>>> starts >>>>>>>>> at 3.455kc and falls 1000 kc for 10 turns CW on the KC knob? >>>>>>>>> I'm asking because I want to know what the frequency of the VFO is >>>>>>>>> supposed >>>>>>>>> to be when the dial is at XX 000 and I presume it's 3.455 kc but >>>>>>> wanting >>>>>>>>> to make sure. >>>>>>>>> Thanks, >>>>>>>>> Barry - N4BUQ >>>>>>>>> ______________________________________________________________ >>>>>>>>> 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 >>>>> ______________________________________________________________ >>>>> 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
