Thanks for all the replies and the suggestions. I don't think I'm brave enough to try to get in there and change coil windings or capacitors in this radio; just too many tuned circuits and some are literally buried under a lot of active circuitry. Disassembling all of that just to get at the coil would be a project beyond my present ability (not that I haven't done that MANY years ago). Also complicating the task is Motorola's use of fabric insulation on the wiring which, by now, has become somewhat brittle, I'm sure. I've seen radios where you just breathe on that wire and the insulation falls off. If I want to build (rebuild) a radio, I think it would probably be a K2 (Hi Hi). I will keep the availability of the capacitors in mind, though. In some of my other projects, that will come in very handy, I'm sure. I did see one reference to slug sizes vs. screw size at Surplus Sales.com. They show the 0.180" as an 8-32 thread and 0.125 as 6-32. If I read that right, maybe finding those slugs won't be as difficult as I first expected. If all else fails and the prototypes do as I expect, I can probably take some brass screws to a machine shop and heve him cut them to length and cut some nice clean slots in the ends for a tuning tool. If anybody is interested, I will follow up with what happens. Also, still looking for a Motrac/Motran (preferably LB) PARTS radio for hardware, etc. so if anybody has a junker, please let me know. Thanks everybody, Tom DGN
--- In [email protected], w7...@... wrote: > > > > Tom, > > > > Your project brings back alot of memories. > > > > I do have a good assortment of low value mica caps (same physical size as > used across helicals). Lots of 2pf on up to at least 10pf. I used many of the > caps to "Pad" coils in "Sensicon" and Motrac rigs, in years gone by. I enjoy > Motrac Stuff.......Still using a Motrac rpt.(100w tube PA). > > > > Let me know off line if you require any caps......Merry Christmas! > > > > Tim W7TRH / AFA0TP Wa. > ----- Original Message ----- > From: "wb6dgn" <tallins...@...> > To: [email protected] > Sent: Wednesday, December 16, 2009 4:17:07 PM GMT -08:00 US/Canada Pacific > Subject: [Repeater-Builder] Re: Source of Coil Slugs > >  > > > > > > > I measured the existing coil slugs as follows; > The slugs for L802 through L809 measure 0.129" at the outside of the threads. > The slugs for coils L301 and L302 measure 0.180" > I didn't measure the slugs for L801, L810 or L811 as those do appear to tune > adequately. > Hope this helps. > Tom DGN > > --- In [email protected] , "wb6dgn" <tallinson2@> wrote: > > > > > > > > Sorry for the lack of detail. The radio is a 42 to 50 Mc. Motran with the > > "L" series receiver (same as used in the Motrac). There are a total of 13 > > tuned circuits in the front end and multiplier but only 3 of them seem to > > tune at all. Those are L801, 810 and 811. The other preselector coils, L802 > > through L809 do not tune nor do the multiplier coils, L301 and L302. > > Interestingly, the radio does receive a local repeater when I tack a short > > piece of wire onto the first mixer input point so, obviously, the > > multiplier chain is on the correct harmonic and has some output at the > > correct frequency. The test set indication is quite low, however, compared > > to the original frequency, so I know that the circuits are not tuned to > > resonance. I am not able to get even a strong signal through the front end, > > though. I did carefully remove all of the related coil slugs without > > breaking any of them and will mic them and repost later this evening. L802 > > through L809 are ABOUT 3/16" dia and L301, 302 are about 1/4" but will give > > more precise measurements later. Thanks much for the replies and > > suggestion. There's a good "old-fashioned" hardware store not too far from > > me, will check with them tomorrow. > > Tom DGN > > > > --- In [email protected] , "Eric Lemmon" <wb6fly@> wrote: > > > > > > Tom, > > > > > > If you identify the make and model of the radio, perhaps someone who has > > > gone this route before can comment. Otherwise, carefully remove one of > > > the > > > slugs and take it to a good hardware store where you can use a thread > > > gauge > > > to identify the thread diameter and pitch. With luck, that store may have > > > machine screws in brass and aluminum that can be trimmed to make the > > > proper > > > slugs. > > > > > > 73, Eric Lemmon WB6FLY > > > > > > > > > -----Original Message----- > > > From: [email protected] > > > [mailto: [email protected] ] On Behalf Of wb6dgn > > > Sent: Tuesday, December 15, 2009 8:46 PM > > > To: [email protected] > > > Subject: [Repeater-Builder] Source of Coil Slugs > > > > > > > > > > > > I'm trying to modify a commercial boat anchor from 42 - 50 Mc. up to the > > > 6 > > > meter ham band. Not even one coil in the RF preselector and 1st > > > oscillator/multiplier chain will tune into the ham band, which is very > > > unusual for this radio. There are just too many tuned circuits to > > > consider > > > removing coil windings or changing capacitors so I want to try using > > > brass > > > or aluminum coil slugs in place of the powdered iron ones now used. Does > > > anyone know of a source for these slugs? I can mic. the slug diameter and > > > guestimate the thread pitch if anyone has any suggestions. TIA for > > > any/all > > > help. > > > Tom DGN > > > > > >
