Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - KK4MSA

Pages: [1]
CB Radio Repair Forum / D201a neutralization question.
« on: July 10, 2019, 11:27:37 PM »
Have a 201a tram here, replaced the electrolytics and high wattage resistors in. Also had to replace the final tube, and I'm following the manual to neutralize and adjusted for -40dc in am and lsb, then it says to retune t700 for maximum dc indication, t700 makes no difference in the -dc at all on the meter, I also have no meter reading in the set/cal position for adjusting the null, it does show rx fine so movement is working, could these 2 issues be related possibly? Is there another way to nutrilize?
Also noteworthy, when meter is hooked to the junction for -dc measurement on the terminal strip, as soon as ac line cord is attached to radio it climbs to about -100ma of -dc.
So have you had any experience with like problem? If so any help is appreciated.

RADIO MODS / Prostar 400 1khz step mod?
« on: November 21, 2016, 10:36:59 PM »
ok, so i have this Prostar400, very similar to thr old magnum 257/eagle sidwinder 400/radio shack htx10. well there is NOTHING online about this prostar not is there a schematic. the problem is, it will only move in 10khz steps. i want it to move in 1khz steps so i can settle on 29.600FM. now on every other model of this radio, there is a step feature. Not on this one, the 6 buttons on the prostar are labeled different that every other model. so im wondering if anyone had ran across this before, or does anyone know how to get this to move in 1khz steps.the chips on the front dace plate in the magnum 257/htx 10 is an sy204m this one is an sy202, so none of the parts are in the right location. any ideas, because this seems to be one of those where the info will have to come from an person rather than a printed schematic.

CB Radio Repair Forum / connex 3300 sort of low squeel/feedback in tx
« on: November 18, 2016, 12:48:03 AM »
got a 3300 here, works, but when tx it has a low squeal or feedback sound in there, not over bearing just in there in and out. i remember reading something about this years ago, but i can not find it anywhere online, any thoughts Buddy? or anyone/

CB Radio Repair Forum / RCI2950 (1st gen) No PLL adjustment at VC1?
« on: November 14, 2016, 11:53:10 PM »
Hello everyone, i have a old 2950 here, works, but had a few problems, so was going to go thru the alignment. started with the PLL, and got to step 3 adjusting for 10.240mhz. the adjustment is VC1, it makes no change in the freq sampled from L61 as instructed. I took VC1 out, and checked it on my lcr meter, print says its a 20pf, and it will adjust a little beyond that, so its working. now the counter is showing 10.240-10.250, what makes it change is turning the radio over or touching the case, i have checked all the grounds on the radio and there all soldered and all screws are tight. but there seems to be something up with the grounding i think, i can not clip ground lead to chassis as it will not settle, meaning it fluctuates quite a bit, i ground it to the incoming 13.8 line and its fine. the coil that comes off the positive and negative to pcb, looks like it has been hot once or twice, there is a little black on it, could that be an issue, if so what can i replace it with, i have quite a few old radios here with similar components from incoming power to pcb.
akso i can touch the case of the radio and the 10.240 will change when i touch the case. i have never had one have an issue with the alignment on the PLL. has anyone else had this issue? I assume the crystal is good as im am seeing 10.240 up to 10.250, i just have no adjustment on vc1.
any ideas?


Pages: [1]