yes, if I were you I would reset all the slugs and try again on the receiver. Sometimes the L receiver (on low band) can be a bear to tune.
Regarding tuning the transmitter, you are correct, there is no "tune" switch. However, if you read the manual about transmitter alignment it does tell you to drop the power supply voltage to something like 11 volts for initial transmitter tuning, then back up to 12.6 volts for final tuning of all stages. good luck ------ Original Message ------ Received: Fri, 18 Dec 2009 09:58:04 PM PST From: "wb6dgn" <tallins...@yahoo.com> To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Source of Coil Slugs > John, > That was my understanding as well and I expected the front end to tune that way. I did just what you described and could not find a peak on any one of the coils. My manual says to start with the slugs (202 through 209) at the top of the forms, which I did. Maybe, before I get too far off the track, I will reset everything and start over again. I was expecting a real easy alignment but with the exception of 201, 210 and 211, nothing seemed to act the way I expected. Interestingly, the transmitter tuned right up with no modifications required. Sure is uncomfortable though not having a "TUNE' switch to reduce input to the final stages while tuning but everything worked out OK. Due to my present wimpy power supply, I only set the output to about 30 watts for now. Thanks for your comments, you've reinforced what I had expected. > Tom DGN > > --- In Repeater-Builder@yahoogroups.com, "JOHN MACKEY" <jmac...@...> wrote: > > > > The 42 to 50 Mhz Motrac/Motran L receiver should tune 6 meters just fine > > EXCEPT for the crystal multiplier stage which will need 3 capacitors changed > > to lower values. > > > > If you are having trouble tuning the RF receiver front end, the manual tells > > you to remove the cover and use a signal generator thru a capacitor to inject > > signal into each stage for tuning the individual adjustments. Then inject > > signal in to the normal RF input and tune the entire front end. > > > > ------ Original Message ------ > > Received: Wed, 16 Dec 2009 04:17:30 PM PST > > From: "wb6dgn" <tallins...@...> > > To: Repeater-Builder@yahoogroups.com > > 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 Repeater-Builder@yahoogroups.com, "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 Repeater-Builder@yahoogroups.com, "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: Repeater-Builder@yahoogroups.com > > > > > [mailto:repeater-buil...@yahoogroups.com] On Behalf Of wb6dgn > > > > > Sent: Tuesday, December 15, 2009 8:46 PM > > > > > To: Repeater-Builder@yahoogroups.com > > > > > 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 > > > > > > > > > > > > > > > > > > > > > > >
