Set screws are spline screws, same as Allen pants different head Sent from my iPhone
> On Jun 16, 2026, at 11:10 PM, [email protected] wrote: > > Send R-390 mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.qth.net/mailman/listinfo/r-390 > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of R-390 digest..." > > > Today's Topics: > > 1. Re: Removing Megacycle Change shaft (Nick England) > 2. Re: Removing Megacycle Change shaft (Nick England) > 3. Re: Weird looking set screws (Jacques Fortin) > 4. Re: Weird looking set screws (Fred Moore) > 5. Re: Removing Megacycle Change shaft (Barry) > 6. Re: Weird looking set screws (Renee K6FSB) > 7. Re: Weird looking set screws (Fred Moore) > 8. Re: Weird looking set screws (Jordan Arndt) > 9. Re: Removing Megacycle Change shaft (Jacques Fortin) > 10. Re: Weird looking set screws (Tisha Hayes) > 11. Re: Weird looking set screws (robert meadows) > 12. Re: Weird looking set screws (Edward Zeranski) > 13. Re: Removing Megacycle Change shaft (Paul Roche) > 14. Re: Weird looking set screws (Dave Merrill) > 15. Re: Weird looking set screws (Fred Moore) > 16. Re: Weird looking set screws (robert meadows) > 17. Re: Weird looking set screws (Barry) > 18. Re: Weird looking set screws (Barry) > 19. Re: Removing Megacycle Change shaft (Jacques Fortin) > 20. Re: Removing Megacycle Change shaft (Paul Roche) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 16 Jun 2026 12:19:20 -0400 > From: Nick England <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: > <CAB55hNcn-GHX=MEJB0XuaP_vOhBdp6+8ONqQ9zY9p+CH1=j...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Reminder FWIW - the R-390A manufacturing drawings are all on line at > https://www.navy-radio.com/rcvrs/r390a/drawings.htm > > You can look in the manual at the parts list to see the drawing number > that covers a particular part. > https://www.navy-radio.com/manuals/r390a-063-2010-7004.pdf > > Have fun, > Nick England K4NYW > Chapel Hill NC > www.navy-radio.com > >> On Tue, Jun 16, 2026 at 11:45?AM rochep--- via R-390 >> <[email protected]> wrote: >> >> Actually I think I just need to get to the gearbox disassembly to the point >> of Steps/Pictures 12-16 in Chapter 10 in the manual. Once I get the gear off >> the MHZ shaft I am good. >> >> From: [email protected] <[email protected]> on >> behalf of rochep--- via R-390 <[email protected]> >> Date: Tuesday, June 16, 2026 at 11:40?AM >> To: Jacques Fortin <[email protected]>; 'Jordan Arndt' >> <[email protected]>; [email protected] <[email protected]> >> Subject: Re: [R-390] Removing Megacycle Change shaft >> >> I agree, taking out the gearbox is what I am looking at. Got alot more to >> learn before getting at this, I assume the entire RF deck and gearbox comes >> out together. Lots of YouTube videos to follow. Thank you all! >> >> Paul >> >> From: Jacques Fortin <[email protected]> >> Date: Tuesday, June 16, 2026 at 11:21?AM >> To: 'Jordan Arndt' <[email protected]>; 'PAUL ROCHE' <[email protected]>; >> [email protected] <[email protected]> >> Subject: RE: [R-390] Removing Megacycle Change shaft >> >> Hi Jordan, >> Not sure about this clamp ID, but it must have a 13/32" hole to fit the gear >> part that it have to hold to the shaft. >> See attached picture. >> The ultimate problem that Paul is facing will be to remove the broken clamp >> there without damaging anything else around. >> Using a two-part clamp is a good idea, medium hard to machine, but there can >> be other hidden mechanical damages in his set. >> We never know what happened to these radios before. >> To maintain (or restore) those requires both electrical and mechanical >> skills. >> >> IMHO, Paul should attempt a gearbox disassembly, cleaning and reassembly >> (Y2K-R3a manual Chapter 10). >> At least, he will be able to catch any other marginal mechanical flaw within >> during the process. >> This is one of the worst case I seen so far: a clamp broken at the worst >> possible place, but.. any other broken clamp within the gearbox will require >> disassembly, anyways. >> >> There is other "stupid" damages I was able to see in my "spare" EAC RF deck >> yesterday night: some of the clamp screws heads are "eaten" internally, most >> probably because someone tried to use Allen bits instead of Bristol ones on >> those. >> That one will be due for a complete overhaul, I believe: it is completely >> gummed up, also. >> >> PAUL: just a comment... >> The answers you provided came to me OK directly to my email address, but the >> same text did not "passed" thru the forum: the postings came to me "empty". >> I cannot tell why, but have a check... >> >> 73, Jacques, VE2JFE in Montreal >> ______________________________________________________________ >> 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 > > > ------------------------------ > > Message: 2 > Date: Tue, 16 Jun 2026 12:24:53 -0400 > From: Nick England <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: > <CAB55hNc72SeQK-AF=metjcpsuyx2uen3z7xrv6xxmwsv8ez...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Maybe the clamp in question is this one? > https://www.navy-radio.com/rcvrs/r390a/drawings/17310-00/00-85-SM-B-170763-CLAMP.pdf > > Nick England K4NYW > Chapel Hill NC > www.navy-radio.com > >> On Tue, Jun 16, 2026 at 12:19?PM Nick England <[email protected]> wrote: >> >> Reminder FWIW - the R-390A manufacturing drawings are all on line at >> https://www.navy-radio.com/rcvrs/r390a/drawings.htm >> >> You can look in the manual at the parts list to see the drawing number >> that covers a particular part. >> https://www.navy-radio.com/manuals/r390a-063-2010-7004.pdf >> >> Have fun, >> Nick England K4NYW >> Chapel Hill NC >> www.navy-radio.com >> >>> On Tue, Jun 16, 2026 at 11:45?AM rochep--- via R-390 >>> <[email protected]> wrote: >>> >>> Actually I think I just need to get to the gearbox disassembly to the point >>> of Steps/Pictures 12-16 in Chapter 10 in the manual. Once I get the gear >>> off the MHZ shaft I am good. >>> >>> From: [email protected] <[email protected]> on >>> behalf of rochep--- via R-390 <[email protected]> >>> Date: Tuesday, June 16, 2026 at 11:40?AM >>> To: Jacques Fortin <[email protected]>; 'Jordan Arndt' >>> <[email protected]>; [email protected] <[email protected]> >>> Subject: Re: [R-390] Removing Megacycle Change shaft >>> >>> I agree, taking out the gearbox is what I am looking at. Got alot more to >>> learn before getting at this, I assume the entire RF deck and gearbox comes >>> out together. Lots of YouTube videos to follow. Thank you all! >>> >>> Paul >>> >>> From: Jacques Fortin <[email protected]> >>> Date: Tuesday, June 16, 2026 at 11:21?AM >>> To: 'Jordan Arndt' <[email protected]>; 'PAUL ROCHE' >>> <[email protected]>; [email protected] <[email protected]> >>> Subject: RE: [R-390] Removing Megacycle Change shaft >>> >>> Hi Jordan, >>> Not sure about this clamp ID, but it must have a 13/32" hole to fit the gear >>> part that it have to hold to the shaft. >>> See attached picture. >>> The ultimate problem that Paul is facing will be to remove the broken clamp >>> there without damaging anything else around. >>> Using a two-part clamp is a good idea, medium hard to machine, but there can >>> be other hidden mechanical damages in his set. >>> We never know what happened to these radios before. >>> To maintain (or restore) those requires both electrical and mechanical >>> skills. >>> >>> IMHO, Paul should attempt a gearbox disassembly, cleaning and reassembly >>> (Y2K-R3a manual Chapter 10). >>> At least, he will be able to catch any other marginal mechanical flaw within >>> during the process. >>> This is one of the worst case I seen so far: a clamp broken at the worst >>> possible place, but.. any other broken clamp within the gearbox will require >>> disassembly, anyways. >>> >>> There is other "stupid" damages I was able to see in my "spare" EAC RF deck >>> yesterday night: some of the clamp screws heads are "eaten" internally, most >>> probably because someone tried to use Allen bits instead of Bristol ones on >>> those. >>> That one will be due for a complete overhaul, I believe: it is completely >>> gummed up, also. >>> >>> PAUL: just a comment... >>> The answers you provided came to me OK directly to my email address, but the >>> same text did not "passed" thru the forum: the postings came to me "empty". >>> I cannot tell why, but have a check... >>> >>> 73, Jacques, VE2JFE in Montreal >>> ______________________________________________________________ >>> 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 > > > ------------------------------ > > Message: 3 > Date: Tue, 16 Jun 2026 13:13:51 -0400 > From: "Jacques Fortin" <[email protected]> > To: "'Fred Moore'" <[email protected]>, "'robert meadows'" > <[email protected]>, "'R390A'" <[email protected]>, "'Tisha > Hayes'" <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset="US-ASCII" > > Hi Fred, > IF EVER you found a valid source for the Bristol ones, let us know ! > Allen head ones are more easy to find... > Use the largest head recess size (3/32"). > But resist the temptation to buy the Stainless Steel ones: these are less > "tough" than the black oxide coated steel ones... > And for the square nuts... I already "made" some from standard 1/4" hex > nuts. > File or grind those on three sides. I prefer brass to the steel ones > however... > > 73, Jacques, VE2JFE in Montreal > > Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head > cap screws for the BFO and BW shaft clamps. One square nut (if available) > would be helpful as well. If not, I'm sure there would be Allen head screws > at my local hardware store. > But What didn't work for the ham I got his from was a mix of slotted and > Phillips screws -- the heads wore out quickly. > -Fred > > > > ------------------------------ > > Message: 4 > Date: Tue, 16 Jun 2026 17:18:14 -0000 > From: "Fred Moore" <[email protected]> > To: "Jacques Fortin" <[email protected]>, "'robert meadows'" > <[email protected]>, "'R390A'" <[email protected]>, "'Tisha > Hayes'" <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1 > > Thanks Jacques, I will do exactly that. I think, too, I will put a TZ-Tape > label on the front edge of the IF that they are Allen head, so as not to trap > the unwary. -Fre4d > > ------ Original Message ------ > Received: Tue, 16 Jun 2026 05:13:59 PM GMT > From: "Jacques Fortin" <[email protected]> > To: "'Fred Moore'" <[email protected]>, "'robert meadows'" > <[email protected]>, "'R390A'" <[email protected]>, "'Tisha > Hayes'" > <[email protected]> > Subject: RE: [R-390] Weird looking set screws > > Hi Fred, > IF EVER you found a valid source for the Bristol ones, let us know ! > Allen head ones are more easy to find... > Use the largest head recess size (3/32"). > But resist the temptation to buy the Stainless Steel ones: these are less > "tough" than the black oxide coated steel ones... > And for the square nuts... I already "made" some from standard 1/4" hex > nuts. > File or grind those on three sides. I prefer brass to the steel ones > however... > > 73, Jacques, VE2JFE in Montreal > > Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head > cap screws for the BFO and BW shaft clamps. One square nut (if available) > would be helpful as well. If not, I'm sure there would be Allen head screws > at my local hardware store. > But What didn't work for the ham I got his from was a mix of slotted and > Phillips screws -- the heads wore out quickly. > -Fred > > > > > > ------------------------------ > > Message: 5 > Date: Tue, 16 Jun 2026 13:20:46 -0400 (EDT) > From: Barry <[email protected]> > To: Jacques Fortin <[email protected]> > Cc: R-390 Mailing List <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: > <[email protected]> > Content-Type: text/plain; charset=utf-8 > > Now that I'm looking directly at the underside of my R390, it's unfortunate > that they changed that assembly for the R390A. That clamp easily comes off > from the front in the earlier model. > > Good luck with it. The R390A's RF deck isn't really that difficult to > remove. It would make any gear cleaning/lubricating a bit easier should you > choose to do so. > > Since I don't have an R390A I can't tell but is that grip ring on the back of > the gearbox all that difficult to remove with the geartrain in place? If > not, then once the pin is removed from that collar, it might be the easiest > to do it that way and the clamp would be easier to remove as well. I realize > it would most likely require a 90-degree grip ring plier with short prongs, > etc. Just a thought... > > Good luck with it. > Barry - N4BUQ > >> Hi Jordan, >> Not sure about this clamp ID, but it must have a 13/32" hole to fit the gear >> part that it have to hold to the shaft. >> See attached picture. >> The ultimate problem that Paul is facing will be to remove the broken clamp >> there without damaging anything else around. >> Using a two-part clamp is a good idea, medium hard to machine, but there can >> be other hidden mechanical damages in his set. >> We never know what happened to these radios before. >> To maintain (or restore) those requires both electrical and mechanical >> skills. >> >> IMHO, Paul should attempt a gearbox disassembly, cleaning and reassembly >> (Y2K-R3a manual Chapter 10). >> At least, he will be able to catch any other marginal mechanical flaw within >> during the process. >> This is one of the worst case I seen so far: a clamp broken at the worst >> possible place, but.. any other broken clamp within the gearbox will require >> disassembly, anyways. >> >> There is other "stupid" damages I was able to see in my "spare" EAC RF deck >> yesterday night: some of the clamp screws heads are "eaten" internally, most >> probably because someone tried to use Allen bits instead of Bristol ones on >> those. >> That one will be due for a complete overhaul, I believe: it is completely >> gummed up, also. >> >> PAUL: just a comment... >> The answers you provided came to me OK directly to my email address, but the >> same text did not "passed" thru the forum: the postings came to me "empty". >> I cannot tell why, but have a check... >> >> 73, Jacques, VE2JFE in Montreal >> >> ______________________________________________________________ >> 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 > > > ------------------------------ > > Message: 6 > Date: Tue, 16 Jun 2026 10:28:35 -0700 > From: Renee K6FSB <[email protected]> > To: Jacques Fortin <[email protected]>, 'Fred Moore' > <[email protected]>, 'robert meadows' <[email protected]>, > 'R390A' <[email protected]>, 'Tisha Hayes' <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > might i suggest next best thing to Bristol spline would be torx which > are not too difficult to obtain and much less chance of cam-out than allen. > Ren?e, K6FSB > > >> On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote: >> Hi Fred, >> IF EVER you found a valid source for the Bristol ones, let us know ! >> Allen head ones are more easy to find... >> Use the largest head recess size (3/32"). >> But resist the temptation to buy the Stainless Steel ones: these are less >> "tough" than the black oxide coated steel ones... >> And for the square nuts... I already "made" some from standard 1/4" hex >> nuts. >> File or grind those on three sides. I prefer brass to the steel ones >> however... >> >> 73, Jacques, VE2JFE in Montreal >> >> Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head >> cap screws for the BFO and BW shaft clamps. One square nut (if available) >> would be helpful as well. If not, I'm sure there would be Allen head screws >> at my local hardware store. >> But What didn't work for the ham I got his from was a mix of slotted and >> Phillips screws -- the heads wore out quickly. >> -Fred >> >> ______________________________________________________________ >> 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 > > > > ------------------------------ > > Message: 7 > Date: Tue, 16 Jun 2026 17:31:04 -0000 > From: "Fred Moore" <[email protected]> > To: <[email protected]>, Jacques Fortin <[email protected]>, 'Fred > Moore' <[email protected]>, 'robert meadows' > <[email protected]>, 'R390A' <[email protected]>, 'Tisha > Hayes' <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1 > > Thanks Renee! -Fred > > ------ Original Message ------ > Received: Tue, 16 Jun 2026 05:29:01 PM GMT > From: Renee K6FSB <[email protected]> > To: Jacques Fortin <[email protected]>, 'Fred Moore' > <[email protected]>, 'robert meadows' <[email protected]>, 'R390A' > <[email protected]>, 'Tisha Hayes' <[email protected]> > Subject: Re: [R-390] Weird looking set screws > > might i suggest next best thing to Bristol spline would be torx which > are not too difficult to obtain and much less chance of cam-out than allen. > Ren?e, K6FSB > > >> On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote: >> Hi Fred, >> IF EVER you found a valid source for the Bristol ones, let us know ! >> Allen head ones are more easy to find... >> Use the largest head recess size (3/32"). >> But resist the temptation to buy the Stainless Steel ones: these are less >> "tough" than the black oxide coated steel ones... >> And for the square nuts... I already "made" some from standard 1/4" hex >> nuts. >> File or grind those on three sides. I prefer brass to the steel ones >> however... >> >> 73, Jacques, VE2JFE in Montreal >> >> Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head >> cap screws for the BFO and BW shaft clamps. One square nut (if available) >> would be helpful as well. If not, I'm sure there would be Allen head > screws >> at my local hardware store. >> But What didn't work for the ham I got his from was a mix of slotted and >> Phillips screws -- the heads wore out quickly. >> -Fred >> >> ______________________________________________________________ >> 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 > > > > > > > ------------------------------ > > Message: 8 > Date: Tue, 16 Jun 2026 11:36:26 -0600 > From: "Jordan Arndt" <[email protected]> > To: "Jacques Fortin" <[email protected]>, "'Fred Moore'" > <[email protected]>, "'robert meadows'" <[email protected]>, > "'R390A'" <[email protected]>, "'Tisha Hayes'" > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <5C025840CD63446D8BE94599F3A49A31@Jordan1> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > I've got 14 of the smaller clamps with the original Bristol hardware and > square nut installed, but I have no idea of their value...I'd have to figure > that out... > 73...Jordan VE6ZT > > > ----- Original Message ----- > From: "Jacques Fortin via R-390" <[email protected]> > To: "'Fred Moore'" <[email protected]>; "'robert meadows'" > <[email protected]>; "'R390A'" <[email protected]>; "'Tisha Hayes'" > <[email protected]> > Sent: Tuesday, June 16, 2026 11:13 AM > Subject: Re: [R-390] Weird looking set screws > > >> Hi Fred, >> IF EVER you found a valid source for the Bristol ones, let us know ! >> Allen head ones are more easy to find... >> Use the largest head recess size (3/32"). >> But resist the temptation to buy the Stainless Steel ones: these are less >> "tough" than the black oxide coated steel ones... >> And for the square nuts... I already "made" some from standard 1/4" hex >> nuts. >> File or grind those on three sides. I prefer brass to the steel ones >> however... >> >> 73, Jacques, VE2JFE in Montreal >> >> Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket >> head >> cap screws for the BFO and BW shaft clamps. One square nut (if available) >> would be helpful as well. If not, I'm sure there would be Allen head >> screws >> at my local hardware store. >> But What didn't work for the ham I got his from was a mix of slotted and >> Phillips screws -- the heads wore out quickly. >> -Fred >> >> ______________________________________________________________ >> 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 > > > > ------------------------------ > > Message: 9 > Date: Tue, 16 Jun 2026 13:36:41 -0400 > From: "Jacques Fortin" <[email protected]> > To: "'Nick England'" <[email protected]> > Cc: 'R390A' <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > Yes, exactly that ! > See attached picture: close to 7/16". > > 73, Jacques, VE2JFE in Montreal > > Hello Nick, > Good try, but the hole on this one is too big (0.435) the one to be replaced > measures 13/32" (0.406). > Maybe the 0.435 ones are for the Kc and Mc knobs, I will check. > > 73, Jacques, VE2JFE in Montreal > > Maybe the clamp in question is this one? > https://www.navy-radio.com/rcvrs/r390a/drawings/17310-00/00-85-SM-B-170763-CLAMP.pdf > Nick England K4NYW > Chapel Hill NC > www.navy-radio.com > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: IMG_5126.JPG > Type: image/jpeg > Size: 2135793 bytes > Desc: not available > URL: > <http://mailman.qth.net/pipermail/r-390/attachments/20260616/46146add/attachment-0001.jpe> > > ------------------------------ > > Message: 10 > Date: Tue, 16 Jun 2026 12:37:59 -0500 > From: Tisha Hayes <[email protected]> > To: [email protected] > Cc: Jacques Fortin <[email protected]>, R390A > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: > <CAACTF10CiEixCXPrM9PW_Mj-kMYkq6aGW_gFV4-TZz+F=f6...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Yes, those Bristol-Spline screws are almost unreasonably durable; You can > torque them to incredible levels and you would almost be certain that the > screw would shear off. The black-oxide ones do seem tougher. > > Torx would be a good replacement, maybe not as high of a torque-out rating > but probably more than enough for the application in a radio. > > About 15 years ago I bought up a bunch of the shaft-collars and > Bristol-Spline screws from FairRadio and I know that I received them. I > used them on two restorations where the hardware was broken/missing. For > the life of me I cannot find any of the ones I thought I had left. > > If someone had been around during the St. Juliens Massacre (when so many > R-390/ 390a's were left to rot) that would of been an excellent source for > an unlimited amount of impossible to find hardware (along with the > mini-BNC's, connectors, plugs, oscillator modules, crystals and slug racks). > > *Ms. Tisha Hayes, AA4HA* > > > > >> On Tue, Jun 16, 2026 at 12:28?PM Renee K6FSB <[email protected]> wrote: >> >> might i suggest next best thing to Bristol spline would be torx which are >> not too difficult to obtain and much less chance of cam-out than allen. >> Ren?e, K6FSB >> >> >> On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote: >> >> Hi Fred, >> IF EVER you found a valid source for the Bristol ones, let us know ! >> Allen head ones are more easy to find... >> Use the largest head recess size (3/32"). >> But resist the temptation to buy the Stainless Steel ones: these are less >> "tough" than the black oxide coated steel ones... >> And for the square nuts... I already "made" some from standard 1/4" hex >> nuts. >> File or grind those on three sides. I prefer brass to the steel ones >> however... >> >> 73, Jacques, VE2JFE in Montreal >> >> Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head >> cap screws for the BFO and BW shaft clamps. One square nut (if available) >> would be helpful as well. If not, I'm sure there would be Allen head screws >> at my local hardware store. >> But What didn't work for the ham I got his from was a mix of slotted and >> Phillips screws -- the heads wore out quickly. >> -Fred >> >> ______________________________________________________________ >> R-390 mailing list >> Home: http://mailman.qth.net/mailman/listinfo/r-390 >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] <[email protected]> >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> > > > ------------------------------ > > Message: 11 > Date: Tue, 16 Jun 2026 18:31:50 +0000 (UTC) > From: robert meadows <[email protected]> > To: "[email protected]" <[email protected]>, Tisha Hayes > <[email protected]> > Cc: Jacques Fortin <[email protected]>, R390A > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=UTF-8 > > McMaster? Carr ha s all you can stand, as well as correct wrenches. > R > On Tuesday, June 16, 2026 at 01:38:37 PM EDT, Tisha Hayes > <[email protected]> wrote: > > Yes, those Bristol-Spline screws are almost unreasonably durable; You can > torque them to incredible levels and you would almost be certain that the > screw would shear off. The black-oxide ones do seem tougher. > Torx would be a good replacement, maybe not as high of a torque-out rating > but probably more than enough for the application in a radio. > About 15 years ago I bought up a bunch of the shaft-collars and > Bristol-Spline screws from FairRadio and I know?that I received them. I used > them on two restorations where the?hardware was broken/missing. For the life > of me I cannot find any of the ones I thought I had left. > If someone had been around during the St. Juliens Massacre (when so many > R-390/ 390a's were left to rot) that would of been an excellent source for an > unlimited amount of impossible to find hardware (along with the mini-BNC's, > connectors, plugs, oscillator modules, crystals and slug racks). > Ms. Tisha Hayes, AA4HA > > > > On Tue, Jun 16, 2026 at 12:28?PM Renee K6FSB <[email protected]> wrote: > > might i suggest next best thing to Bristol spline would be torx which are > not too difficult to obtain and much less chance of cam-out than allen. > Ren?e, K6FSB > > > On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote: > > Hi Fred, > IF EVER you found a valid source for the Bristol ones, let us know ! > Allen head ones are more easy to find... > Use the largest head recess size (3/32"). > But resist the temptation to buy the Stainless Steel ones: these are less > "tough" than the black oxide coated steel ones... > And for the square nuts... I already "made" some from standard 1/4" hex > nuts. > File or grind those on three sides. I prefer brass to the steel ones > however... > > 73, Jacques, VE2JFE in Montreal > > Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head > cap screws for the BFO and BW shaft clamps. One square nut (if available) > would be helpful as well. If not, I'm sure there would be Allen head screws > at my local hardware store. > But What didn't work for the ham I got his from was a mix of slotted and > Phillips screws -- the heads wore out quickly. > -Fred > > ______________________________________________________________ > 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 > > > > > > ------------------------------ > > Message: 12 > Date: Tue, 16 Jun 2026 12:06:18 -0700 > From: Edward Zeranski <[email protected]> > To: [email protected], Renee K6FSB <[email protected]> > Cc: Jacques Fortin <[email protected]>, R390A > <[email protected]>, Tisha Hayes <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8 > > Have you looked at McMaster Carr or Granger? When I was working we bought > Bristol/Bristo wrenches from them. Also do a search for TechniTool in PA. > EdZ KG6UTS > > Sent from my iPhone > >> On Jun 16, 2026, at 10:28, Renee K6FSB via R-390 <[email protected]> >> wrote: >> >> ?might i suggest next best thing to Bristol spline would be torx which are >> not too difficult to obtain and much less chance of cam-out than allen. >> Ren?e, K6FSB >> >> >>>> On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote: >>> Hi Fred, >>> IF EVER you found a valid source for the Bristol ones, let us know ! >>> Allen head ones are more easy to find... >>> Use the largest head recess size (3/32"). >>> But resist the temptation to buy the Stainless Steel ones: these are less >>> "tough" than the black oxide coated steel ones... >>> And for the square nuts... I already "made" some from standard 1/4" hex >>> nuts. >>> File or grind those on three sides. I prefer brass to the steel ones >>> however... >>> >>> 73, Jacques, VE2JFE in Montreal >>> >>> Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head >>> cap screws for the BFO and BW shaft clamps. One square nut (if available) >>> would be helpful as well. If not, I'm sure there would be Allen head screws >>> at my local hardware store. >>> But What didn't work for the ham I got his from was a mix of slotted and >>> Phillips screws -- the heads wore out quickly. >>> -Fred >>> >>> ______________________________________________________________ >>> 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 > > > > ------------------------------ > > Message: 13 > Date: Tue, 16 Jun 2026 16:35:09 -0400 > From: Paul Roche <[email protected]> > To: Jacques Fortin <[email protected]> > Cc: R390A <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8 > > When I reply to all on email I was told there is no VK tent and when I try to > respond to a post online I get an error message can I not ?reply to all? > from my phone? > Sent from my iPhone > >> On Jun 16, 2026, at 1:37?PM, Jacques Fortin via R-390 >> <[email protected]> wrote: >> >> ?Yes, exactly that ! >> See attached picture: close to 7/16". >> >> 73, Jacques, VE2JFE in Montreal >> >> Hello Nick, >> Good try, but the hole on this one is too big (0.435) the one to be replaced >> measures 13/32" (0.406). >> Maybe the 0.435 ones are for the Kc and Mc knobs, I will check. >> >> 73, Jacques, VE2JFE in Montreal >> >> Maybe the clamp in question is this one? >> https://www.navy-radio.com/rcvrs/r390a/drawings/17310-00/00-85-SM-B-170763-CLAMP.pdf >> Nick England K4NYW >> Chapel Hill NC >> www.navy-radio.com >> <IMG_5126.JPG> >> ______________________________________________________________ >> 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 > > > > ------------------------------ > > Message: 14 > Date: Tue, 16 Jun 2026 16:36:01 -0500 > From: Dave Merrill <[email protected]> > Cc: Jacques Fortin <[email protected]>, R390A > <[email protected]>, [email protected], Tisha Hayes > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: > <cagrti8xc4j+m5vm8kvpvnbpk4dknsu-+e2-mx7sw7ftxcha...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > A couple of years ago I tried to locate any supplier of Bristol screws and > was very disappointed to find that they have been out of production for > decades and the tooling to make them is also gone. > > You can have them made but the upfront costs are sky high and out of reach > for hobbists. > > --... ...-- Dave N9ZC > > > ------------------------------ > > Message: 15 > Date: Tue, 16 Jun 2026 21:51:00 -0000 > From: "Fred Moore" <[email protected]> > To: robert meadows <[email protected]>, "[email protected]" > <[email protected]>, Tisha Hayes <[email protected]> > Cc: Jacques Fortin <[email protected]>, R390A > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=UTF-8 > > Hi Robert, > > Thank you. I have a set of Bristol wrenches. But as Jacques exclaimed, > locating new Bristol head cap screws appears to be an impossibility. If > found, they would be from a source selling flight-qualified fasteners. For > example, this place in my home state: www.planepartsinc.com -- "We are the > nuts and bolts of your plane needs." Doesn't that sound promising? But alas, > no. > > I just picked up 10 of the black Allen head cap screws from Ace Hardware. > > -Fred > > > > ------ Original Message ------ > Received: Tue, 16 Jun 2026 06:32:08 PM GMT > From: robert meadows <[email protected]> > To: "[email protected]" <[email protected]>, Tisha Hayes <[email protected]>Cc: > Jacques Fortin <[email protected]>, Fred Moore <[email protected]>, > R390A <[email protected]> > Subject: Re: [R-390] Weird looking set screws > > McMaster? Carr ha s all you can stand, as well as correct wrenches. > R > On Tuesday, June 16, 2026 at 01:38:37 PM EDT, Tisha Hayes > <[email protected]> wrote: > > Yes, those Bristol-Spline screws are almost unreasonably durable; You can > torque them to incredible levels and you would almost be certain that the > screw would shear off. The black-oxide ones do seem tougher. > Torx would be a good replacement, maybe not as high of a torque-out rating but > probably more than enough for the application in a radio. > About 15 years ago I bought up a bunch of the shaft-collars and Bristol-Spline > screws from FairRadio and I know?that I received them. I used them on two > restorations where the?hardware was broken/missing. For the life of me I > cannot find any of the ones I thought I had left. > If someone had been around during the St. Juliens Massacre (when so many > R-390/ 390a's were left to rot) that would of been an excellent source for an > unlimited amount of impossible to find hardware (along with the mini-BNC's, > connectors, plugs, oscillator modules, crystals and slug racks). > Ms. Tisha Hayes, AA4HA > > > > On Tue, Jun 16, 2026 at 12:28?PM Renee K6FSB <[email protected]> wrote: > > might i suggest next best thing to Bristol spline would be torx which are > not too difficult to obtain and much less chance of cam-out than allen. > Ren?e, K6FSB > > > On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote: > > Hi Fred, > IF EVER you found a valid source for the Bristol ones, let us know ! > Allen head ones are more easy to find... > Use the largest head recess size (3/32"). > But resist the temptation to buy the Stainless Steel ones: these are less > "tough" than the black oxide coated steel ones... > And for the square nuts... I already "made" some from standard 1/4" hex > nuts. > File or grind those on three sides. I prefer brass to the steel ones > however... > > 73, Jacques, VE2JFE in Montreal > > Aha! I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head > cap screws for the BFO and BW shaft clamps. One square nut (if available) > would be helpful as well. If not, I'm sure there would be Allen head screws > at my local hardware store. > But What didn't work for the ham I got his from was a mix of slotted and > Phillips screws -- the heads wore out quickly. > -Fred > > ______________________________________________________________ > 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 > > > > > > > > > ------------------------------ > > Message: 16 > Date: Tue, 16 Jun 2026 21:58:52 +0000 (UTC) > From: robert meadows <[email protected]> > To: Dave Merrill <[email protected]> > Cc: Jacques Fortin <[email protected]>, R390A > <[email protected]>, "[email protected]" <[email protected]>, Tisha > Hayes <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: <[email protected]> > Content-Type: text/plain; charset=UTF-8 > > I seem to remember speaking with the Bristol folks a year or so ago, and was > advised, still available.R > On Tuesday, June 16, 2026 at 05:36:25 PM EDT, Dave Merrill via R-390 > <[email protected]> wrote: > > A couple of years ago I tried to locate any supplier of Bristol screws and > was very disappointed to find that they have been out of production for > decades and the tooling to make them is also gone. > > You can have them made but the upfront costs are sky high and out of reach > for hobbists. > > --... ...-- Dave N9ZC > ______________________________________________________________ > 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 > > > ------------------------------ > > Message: 17 > Date: Tue, 16 Jun 2026 18:15:03 -0400 (EDT) > From: Barry <[email protected]> > To: Robert Meadows <[email protected]> > Cc: Jacques Fortin <[email protected]>, R-390 Mailing List > <[email protected]>, k6fsb <[email protected]>, Tisha Hayes > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: > <[email protected]> > Content-Type: text/plain; charset=utf-8 > > Apologies if this has already been mentioned, but these look somewhat > promising. I have no idea, though, how much they'd cost or even if they're > Bristol drive but the description sounds like they are. > > https://www.mwcomponents.com/shop/4-40x-250-sh-188-spl > > Barry - N4BUQ > >> I seem to remember speaking with the Bristol folks a year or so ago, and was >> advised, still available.R >> On Tuesday, June 16, 2026 at 05:36:25 PM EDT, Dave Merrill via R-390 >> <[email protected]> wrote: >> >> A couple of years ago I tried to locate any supplier of Bristol screws and >> was very disappointed to find that they have been out of production for >> decades and the tooling to make them is also gone. >> >> You can have them made but the upfront costs are sky high and out of reach >> for hobbists. >> >> --... ...-- Dave N9ZC >> ______________________________________________________________ >> 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 > > > ------------------------------ > > Message: 18 > Date: Tue, 16 Jun 2026 18:16:55 -0400 (EDT) > From: Barry <[email protected]> > To: Barry <[email protected]> > Cc: Jacques Fortin <[email protected]>, R-390 Mailing List > <[email protected]>, k6fsb <[email protected]>, Tisha Hayes > <[email protected]> > Subject: Re: [R-390] Weird looking set screws > Message-ID: > <[email protected]> > Content-Type: text/plain; charset=utf-8 > > Rats. I just realized those are only 1/4" long so, even if they are Bristol > spline drive, they're too short for this use. > > Barry - N4BUQ > >> Apologies if this has already been mentioned, but these look somewhat >> promising. >> I have no idea, though, how much they'd cost or even if they're Bristol drive >> but the description sounds like they are. >> >> https://www.mwcomponents.com/shop/4-40x-250-sh-188-spl >> >> Barry - N4BUQ >> >>> I seem to remember speaking with the Bristol folks a year or so ago, and was >>> advised, still available.R >>> On Tuesday, June 16, 2026 at 05:36:25 PM EDT, Dave Merrill via R-390 >>> <[email protected]> wrote: >>> >>> A couple of years ago I tried to locate any supplier of Bristol screws and >>> was very disappointed to find that they have been out of production for >>> decades and the tooling to make them is also gone. >>> >>> You can have them made but the upfront costs are sky high and out of reach >>> for hobbists. >>> >>> --... ...-- Dave N9ZC >>> ______________________________________________________________ >>> 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 > > > ------------------------------ > > Message: 19 > Date: Tue, 16 Jun 2026 22:08:36 -0400 > From: "Jacques Fortin" <[email protected]> > To: "'Nick England'" <[email protected]> > Cc: 'R390A' <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > Here is the needed clamp. > > 73, Jacques, VE2JFE in Montreal > > Hello Nick, > Good try, but the hole on this one is too big (0.435) the one to be replaced > measures 13/32" (0.406). > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: 00-99-SM-B-178486-CLAMP.pdf > Type: application/pdf > Size: 286463 bytes > Desc: not available > URL: > <http://mailman.qth.net/pipermail/r-390/attachments/20260616/0157be6e/attachment-0001.pdf> > > ------------------------------ > > Message: 20 > Date: Tue, 16 Jun 2026 23:08:58 -0400 > From: Paul Roche <[email protected]> > To: Jacques Fortin <[email protected]> > Cc: R390A <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > A non-text attachment was scrubbed... > Name: image0.jpeg > Type: image/jpeg > Size: 674032 bytes > Desc: not available > URL: > <http://mailman.qth.net/pipermail/r-390/attachments/20260616/c2954e6e/attachment.jpeg> > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: image1.jpeg > Type: image/jpeg > Size: 999865 bytes > Desc: not available > URL: > <http://mailman.qth.net/pipermail/r-390/attachments/20260616/c2954e6e/attachment-0001.jpeg> > -------------- next part -------------- > > Sent from my iPhone > I dont know if you can get see this. Now what? I see how to remove the KHZ > gear but not sure about the clutch disk and the ?gear? above it. > > Paul >> On Jun 16, 2026, at 10:09?PM, Jacques Fortin via R-390 >> <[email protected]> wrote: >> >> ?Here is the needed clamp. >> >> 73, Jacques, VE2JFE in Montreal >> >> Hello Nick, >> Good try, but the hole on this one is too big (0.435) the one to be replaced >> measures 13/32" (0.406). >> <00-99-SM-B-178486-CLAMP.pdf> >> ______________________________________________________________ >> 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 > [email protected] > http://mailman.qth.net/mailman/listinfo/r-390 > > > End of R-390 Digest, Vol 263, Issue 11 > ************************************** ______________________________________________________________ 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
