We all enjoy these rigs, Bob. If it was me, I'd try one part at a time and hook it up to a regulated supply and a counter. You can then log the frequency every time you walk by and see, over time, if changing the part fixed the problem. I'd start with just the PTO before replacing anything. Log what the counter is telling you any time you happen to look over at it. Don't destroy any parts in case you find you've made matters worse so you can return to the zero point.
Steve Wedge, W1ES/4 "I can't complain, but sometimes I still do." - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! ----- Original Message ----- From: Robert Fish To: [email protected] Sent: Wednesday, October 26, 2011 3:28 PM Subject: Re: [Drakelist] T-4XC PTO chirps Garey, Eddy, Paul, Curt and Steve, Thanks for the quick replies guys. This is a great bunch on this list. I am convinced that it is the PTO. If I lightly tap on the PTO can with a pencil tip (and I mean very lightly) it causes the signal to jump around. Maybe just a cold solder joint. I have a parts radio (T-4XC) with a PTO in it. I guess I'll haul it out and test it. If it's stable, I will swap it with the faulty one. Can I then rebuild (shotgun) the bad PTO with all new parts? or is there special parts in there that I have to be careful with? I probably have most of the stuff in stock (NPO caps, metal film resistors etc.). It would be handy to have a nice new spare because I also have a B-Line. Also, A 5Mhz PTO is a nice thing to have around, homebrew QRP rigs etc. I have a HP signal generator, so I think I will try Paul's suggestion on the Lissajous display. Perhaps I can find the faulty component with some freeze spray and make this a quick repair. Maybe learn something in the process (heaven forbid). I wrote this e-mail in three sittings as real life keeps intervening. The bottom line is, thanks for all the help, I will let you know how I proceed and the results thereof. 73, Bob K6GGO On 2011-10-26, at 1:16 PM, Steve Wedge wrote: Removing the PTO - at least with the A's and B's - requires removal of the front panel. This is a good time to clean it as well as the fiducial window. Use only dish soap for the window or you'll take off the red line! Hi Guys, Well, I can not vouch for the "A" & "B" series, but in my T-4X transmitter that extensive a dis-aasembly is most assuredly NOT required... After removing the three tubes immediately behind the PTO can, the can itself is extricated by first dis-connecting the top grounding spring, & then lightly squeezing together the "side prongs" that hold the can in place, one prong at a time (this is by far the WORSE part of the operation, and the most time-consuming). The can is slipped off the assembly, rearward (where the 3 tubes were). Next, with a pair of long needle-nose pliers, each brass spacer that you see at the front of the vertical PTO board is grasped (so the spacers won't fall & get lost), and a slotted screw driver is used to unscrew the 4 screws that go through them. The PTO board & coil assembly is now loose, save for the 3 wires that are attached to the front vertical board: draw a simple sketch showing where these are connected so that you'll remember when you re-assemble everything, then touch each point on the board with a soldering iron to release each wire... The entire assembly is then slipped back off of the brass rod with the ferrite slugs on it. Absolutely no need to remove the front panel, no need for anything that complicated, or involved... To re-assemble, simply reverse this procedure! Hi Hi ~73~ de Eddy VE3CUI - VE3XZ ------------------------------------------------------------------------------ _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
_______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
