Search found 618 matches

by kcbooboo
Thu Jan 14, 2021 8:31 am
Forum: STL Engineering
Topic: Marti frequency control module temperature
Replies: 4
Views: 636

Re: Marti frequency control module temperature

A Moseley PCL6000 manual claims (in several places) their crystal ovens operate at 65C. I would think they have to run at slightly above the maximum temperature the unit is rated for, such that the crystal will always be higher than the highest ambient operating temperature expected. That manual say...
by kcbooboo
Thu Nov 05, 2020 7:09 am
Forum: Everything else
Topic: Bought a New LCR Meter
Replies: 7
Views: 681

Re: Bought a New LCR Meter

When I was looking for Kelvin-style (4-wire) test leads and clips, about 98% of the Asian-made ones had the four wires, but ran two wires to just one side of each clip. Fat lot of good that does. I ended up rolling my own, with decent flexible wire, my own recessed banana plugs, and clips that reall...
by kcbooboo
Fri Oct 16, 2020 12:34 pm
Forum: FM Radio
Topic: New member - LPFM transmitter recommendations
Replies: 35
Views: 5157

Re: New member - LPFM transmitter recommendations

Interesting and well-written story. I suspect that the foam filters that were originally in the VS300 passed a lot more air than the mesh-type you replaced them with. There are dozens of filters out there with different "pores per inch" and most TX mfgrs don't tell you what that value shou...
by kcbooboo
Mon Oct 05, 2020 12:35 pm
Forum: Everything else
Topic: FIELD INTENSITY METER CALIBRATION
Replies: 10
Views: 694

Re: FIELD INTENSITY METER CALIBRATION

The hard part is getting a "standard field" of known intensity to set the output level of the CAL OSC so the FI meter reads correctly. There are a lot of adjustments but most can be checked with a good RF sig gen and/or a step attenuator. The various manuals go through the IF stage tuning ...
by kcbooboo
Thu Sep 17, 2020 4:43 am
Forum: FM Radio
Topic: Quality translator
Replies: 22
Views: 923

Re: Quality translator

I believe the BPF was a brand "S". 3 cavities in a triangular configuration. I never swept them, so it's possible they weren't tuned to the correct frequency. The BPF was a requirement at the site due to other translators already present. I think the BPF was quickly bypassed and we still s...
by kcbooboo
Wed Sep 16, 2020 5:57 am
Forum: FM Radio
Topic: Quality translator
Replies: 22
Views: 923

Re: Quality translator

I'll also recommend Nautel VS300. But be aware that these units run on 240VAC and you'll need a step-up transformer, which they'll gladly sell you, if using them in a 120VAC environment. They can be bought with a good audio processor built-in. Add a small Inovonics receiver and you're off and runnin...
by kcbooboo
Sat Jul 18, 2020 4:16 am
Forum: STL Engineering
Topic: Marti STL-10 regulator
Replies: 13
Views: 640

Re: Marti STL-10 regulator

The STL-10 manual has a block/wiring diagram. They use 13VAC for the meter illumination but there's no reason it can't be 12VDC or even less if you want longer bulb life.

Bob M.
by kcbooboo
Tue Jul 07, 2020 3:54 am
Forum: FCC Discussion
Topic: AM station to shut down at end of May 2019
Replies: 30
Views: 3847

Re: AM station to shut down at end of May 2019

If they were signs of life, it wasn't a very long life. Perhaps we were just lucky to hear the NWS being broadcast as fill-in programming. The one application I saw mentioned the "new" callsign had been applied for back as far as 1980, which seems quite odd, as Ryan was not even alive back...
by kcbooboo
Sun Jul 05, 2020 6:00 pm
Forum: FCC Discussion
Topic: AM station to shut down at end of May 2019
Replies: 30
Views: 3847

Re: AM station to shut down at end of May 2019

As Gomer Pyle would say, "Well, surprise, surprise!" A couple of weeks ago when I was looking for a decent news station to listen to at night, I tuned my radio up the band and heard the unmistakeable mechanical voice of the National Weather Service station on my AM radio, right about where...
by kcbooboo
Tue Jun 30, 2020 11:55 am
Forum: AM Radio
Topic: FIM-21/ 41 Repairs
Replies: 9
Views: 939

Re: FIM-21/ 41 Repairs

Mooretronix claims to be able to calibrate the RCA WX-2 series and the Nems-Clarke 120 series as well as the PI FIM-21 and FIM-41. I don't know how their service compares to what PI used to do, but it IS at least an alternative.

http://www.mooretronix.com/news.php

Bob M.
by kcbooboo
Mon Jun 29, 2020 5:20 am
Forum: AM Radio
Topic: FIM-21/ 41 Repairs
Replies: 9
Views: 939

Re: FIM-21/ 41 Repairs

My FIM-41 experience several years ago was horrible. They claimed my unit had been submerged in salt water. There was some light powdery residue on the IC sockets, around the star lockwashers in the chassis, and some green gunk around one capacitor lead. They apparently don't "fix" anythin...
by kcbooboo
Thu Jun 04, 2020 3:21 am
Forum: FM Radio
Topic: Digit or Digit-CD full manuals
Replies: 28
Views: 1589

Re: Digit or Digit-CD full manuals

Thanks for the info. I didn't see anything odd when I measured the pin, but since none of those signals are being used at all, the cable could be disconnected at the front panel and taped up and it would never bother anyone again. That's easier to get to than at the rear of the chassis. I'll let the...
by kcbooboo
Wed Jun 03, 2020 4:04 am
Forum: FM Radio
Topic: Digit or Digit-CD full manuals
Replies: 28
Views: 1589

Re: Digit or Digit-CD full manuals

Final report: After running the unit on and off for 8-12 hours per day over the past two weeks, I dragged the unit up to my bench. My wideband wattmeter read about one watt lower than the front panel meter but that's close enough. Initially the frequency was slowly cycling about +/- 15 Hz of its pro...
by kcbooboo
Sun May 17, 2020 4:05 am
Forum: FM Radio
Topic: Parting out Harris 3.5K
Replies: 13
Views: 1204

Re: Parting out Harris 3.5K

That model has a touch screen that's embedded in the shielded front panel. When you touch the panel, the transparent aluminum becomes clear and you can see the screen inside it.

Bob M.
by kcbooboo
Fri May 15, 2020 5:21 am
Forum: FM Radio
Topic: Digit or Digit-CD full manuals
Replies: 28
Views: 1589

Re: Digit or Digit-CD full manuals

Yesterday I took the entire unit apart: front panel off, inside shelf out, just to get to the digital modulator that's mounted to the inside of the rear panel. Even after all that, it still resisted and the flat cable got hung up on an edge of the PA heat sink. But I persisted and finally got it out...