Search found 916 matches

by TPT
Fri Feb 28, 2020 7:54 am
Forum: FM Radio
Topic: Collins 831G schematic
Replies: 11
Views: 336

Re: Collins 831G schematic

Which we (Fireman No, 1 and me, Fireman No. 2) have been urging them to do--(convert to 50 ohm input, that is). Then get a solid state kilowatt transmitter to drive the final (believe about 600 watts drive is needed). Which could then be used as a back-up when something else breaks. The two small op...
by TPT
Thu Feb 27, 2020 10:10 am
Forum: General Computers
Topic: Lexicon Alpha--no output
Replies: 0
Views: 1504

Lexicon Alpha--no output

Have an Asus tower in a production studio. Using a Lexicon Alpha. Something happened, probably a Windows 10 update. Now we can get audio into the Alpha, but playback is either very "distorted" (sounds like a bit rate error problem) or just white noise. Interesting my IT guru (who is 1000 miles away ...
by TPT
Thu Feb 27, 2020 7:18 am
Forum: FM Radio
Topic: Collins 831G schematic
Replies: 11
Views: 336

Re: Collins 831G schematic

The 816 manual has a copy of the schematic, which can be blown up enough to see what is going on. Next step is to crawl in to see if I can figure out what is actually in there compared to the schematic. May just take a clip lead off the "tune" capacitor to ground to see if that helps. L-9 is a slide...
by TPT
Tue Feb 25, 2020 4:33 pm
Forum: FM Radio
Topic: Collins 831G schematic
Replies: 11
Views: 336

Re: Collins 831G schematic

They had a 831 manual--in pieces. I've scanned that (luckily, I have a sheet-fed scanner), but, as I mentioned, the full scale schematic was in a pouch in the original manual cover--long gone. The IPA assembly is in a box mounted below the final tube socket, the tubes are accessible from the left ca...
by TPT
Tue Feb 25, 2020 7:16 am
Forum: FM Radio
Topic: Collins 831G schematic
Replies: 11
Views: 336

Re: Collins 831G schematic

Thanks...overall schematic is on page 161 of that manual. Looking at it, I can't figure out how this thing ever worked. The "Couple" cap, C34, is mounted to a "U" shaped bracket which is connected to the grids of the two 4CX250B tubes. The variable side of this open frame cap has a tab that the inco...
by TPT
Mon Feb 24, 2020 1:09 pm
Forum: FM Radio
Topic: Collins 831G schematic
Replies: 11
Views: 336

Collins 831G schematic

Station was using a BE FX50 as an exciter, the Darlingtons went out and it went to a full 50 watts. While I had the BE out for repair, put in a 35 watt Bext exciter to keep the station on. Reflected power problems--as much coming back as being fed to the IPA. Now the 831 has a tube IPA, the match to...
by TPT
Mon Feb 24, 2020 12:55 pm
Forum: AM Radio
Topic: Orban Optimod 9300/9400
Replies: 6
Views: 290

Re: Orban Optimod 9300/9400

Yep, when I see AM I think voice programming. Not necessarily true.
by TPT
Sun Feb 23, 2020 6:32 pm
Forum: AM Radio
Topic: Orban Optimod 9300/9400
Replies: 6
Views: 290

Re: Orban Optimod 9300/9400

Makes more sense to insert something like a Symetrix 528E in the program line--and use that to feed the audio stream.

After all, most folks are going to listen to the stream on a little plastic computer speaker, or even off their phone. So moderately processed audio will sound fine.
by TPT
Sun Feb 09, 2020 9:49 am
Forum: FCC Discussion
Topic: EAS Monitoring Requirements
Replies: 7
Views: 394

Re: EAS Monitoring Requirements

Here we go, digging deeper in their state plan. The local primary-1 is KYTE in Independance, Oregon, 27 miles away, while the secondary local primary (LP2) is 97.5, KSHL, in Lincoln Beach, which appears to be only 10 miles away. You would monitor one of those two stations (or both). The Local Primar...
by TPT
Sun Feb 09, 2020 9:36 am
Forum: FCC Discussion
Topic: EAS Monitoring Requirements
Replies: 7
Views: 394

Re: EAS Monitoring Requirements

Supposedly the Commission was going to set up a standardized state plans. Never saw what became of that idea. Some state plans are good, some are concocted by good-old-boys in the state capital over lunch. I take care of one full power noncom (900 watts at 160' AHAAT--but it is the only radio statio...
by TPT
Wed Feb 05, 2020 4:28 pm
Forum: General Computers
Topic: Another Win10 update
Replies: 1
Views: 1343

Another Win10 update

Just what I needed after Super Bowl weekend. Sales computer took 4 hours, my little Dell back in the shop got started Monday afternoon--did not get in Tuesday--still "chasing its tail" Wednesday morning. Outlook was disabled on two computers (port closed somehow). Then another computer suddenly star...
by TPT
Wed Jan 29, 2020 6:43 am
Forum: FCC Discussion
Topic: Renewal season
Replies: 3
Views: 441

Re: Renewal season

I would file in the month before the renewal filing is due. So if the renewal has to be filed by April 1st, file in March. Otherwise there is a risk that an early filing might be kicked out by the system, but the notice would be sent to the wrong place--or not at all. Leaving the station's license a...
by TPT
Sun Jan 26, 2020 9:16 am
Forum: AM Radio
Topic: Another one bites the dust
Replies: 10
Views: 882

Re: Another one bites the dust

Despite the enthusiasm of the low power community, these stations are very subject to going silent. There were six LP's in my area--only two remain on the air. Two licenses were turned in, a third high school station never filed for renewal last June. The renewal period for the fourth begins in June...
by TPT
Tue Jan 14, 2020 7:37 pm
Forum: AM Radio
Topic: Gates 5--no audio
Replies: 28
Views: 1303

Re: Gates 5--no audio

The jumper is on the PDM amp board. On the 5, the jumper is in one position, on the 1 kw, in the other position.
by TPT
Tue Jan 14, 2020 7:13 am
Forum: AM Radio
Topic: Gates 5--no audio
Replies: 28
Views: 1303

Re: Gates 5--no audio

Nothing like that, although there is audio on the carrier now. I see a narrow spike, and a sine wave (at very low level) with something riding on it. Changed jumpers on the PDM amp cards to get audio. Best guess is the round IC's U12/U15 are bad, which are going to be next to impossible to replace. ...