Search found 987 matches

by TPT
Sat May 18, 2013 7:02 am
Forum: FM Radio
Topic: Sibilance
Replies: 2
Views: 4009

Re: Sibilance

Two other possibilities: 1. Certain vintages of STL-10's have switches to set pre-emphasis (they're on the audio boards). Age/dirt/ etc. may cause these switches to become flaky and intermittent--which would change the pre-emphasis applied to the audio. Solution is to replace the switches, or remove...
by TPT
Fri May 17, 2013 5:15 pm
Forum: Ask the Engineers
Topic: Cband interference
Replies: 7
Views: 2878

Re: Cband interference

We had a TI (terrestrial interference) problem for years because there was an MCI tower directly behind our dish. What we did is put up three short pieces of tower stock behind the dish, (the small 12" stock that used to be used for TV antennas) and string hardware cloth between them. Proved to...
by TPT
Tue May 07, 2013 5:00 pm
Forum: AM Radio
Topic: PSRA, PSSA on FCC site
Replies: 15
Views: 2701

Re: PSRA, PSSA on FCC site

On the other hand, you could create a special class of translator--say a kilowatt @ 100 ft AHAAT--and if you can engineer it in you get it--if you agree to dismantle or disable (photos/affidavit required) your AM site within so many days after the covering license is issued. Would be a step in the r...
by TPT
Thu May 02, 2013 6:47 pm
Forum: FM Radio
Topic: Optimod TV used to process FM audio?
Replies: 16
Views: 3120

Re: Optimod TV used to process FM audio?

From the prices I've seen for used 9100's it makes more sense to just bite the bullet and buy a modern FM processor such as an Omnia One. Leave the pilot on, feed it left and right from your console (you're going to end up with a stereo console--try buying anything else) & talk to the folks in C...
by TPT
Sat Apr 27, 2013 3:40 pm
Forum: Ask the Engineers
Topic: Help Needed for Audio Signal chain for a TV station
Replies: 16
Views: 3002

Re: Help Needed for Audio Signal chain for a TV station

Installation may prove to be the critical phase of the project, rather than which mixer is selected. Light dimmers and other studio equipment can introduce noise into the mike feeds, for example. Try to use as many balanced sources as possible, and you may wish to budget in outboard hi-fi to balance...
by TPT
Thu Apr 18, 2013 5:10 pm
Forum: FM Radio
Topic: Missouri FM Transmitter Fire/ Parts NEED
Replies: 4
Views: 1171

Re: Missouri FM Transmitter Fire/ Parts NEED

Believe I have a connector for a 3" cable--not sure of manufacturer. If you are interested let me know, & I'll let you have it for the cost of shipping.

I also have some 3" elbows.

RF specialties probably can get you a reducer to N fairly quickly.
by TPT
Tue Apr 16, 2013 4:08 pm
Forum: FM Radio
Topic: HT10 will not fully produce power
Replies: 4
Views: 1139

Re: HT10 will not fully produce power

One contrary darn transmitter--been fighting one for almost a year. There is a board with several Darlingtons and one very expensive voltage regulator that sits between the IPA power supply and the IPA. You might want to take a look at that. The OVLD position on the multimeter connects to another sw...
by TPT
Tue Apr 09, 2013 5:39 am
Forum: FM Radio
Topic: The Ultimate pirate?
Replies: 13
Views: 2130

Re: The Ultimate pirate?

There is also an ITU standard which essentially attacks compression. Different than deviation.
If you can find one, compare an Optimod 8000 with 3 db of compression with an 8100 with 5 db.
by TPT
Mon Apr 08, 2013 5:37 am
Forum: FM Radio
Topic: The Ultimate pirate?
Replies: 13
Views: 2130

Re: The Ultimate pirate?

Hmmm...a little vague. I get the impression that this station is in Ireland, but right on the border, using the vertical DA array to get into Belfast. So the Irish authorities are playing Sgt Schultz (I hear nothing!). The quote about FCC/CRTC specs refer to deviation, i.e modulation standards. A nu...
by TPT
Sun Mar 24, 2013 6:56 am
Forum: AM Radio
Topic: relocating AM station, ground conductivity
Replies: 5
Views: 1742

Re: relocating AM station, ground conductivity

I suspect you are on the right track. Unfortunate, but the future of AM is often on an FM translator. Unless this is a very minor move, say, under a mile, you will need to show that the station from the new site does not interfere with other stations. This is usually theoretical, based on the estima...
by TPT
Wed Mar 20, 2013 4:25 pm
Forum: FM Radio
Topic: Harris HT10
Replies: 4
Views: 2097

Re: Harris HT10

Found the problem--combination of things. 1. The screen Kapton was apparently bad, although no way to tell by just looking at it. 2. The automatic power control circuit likes to turn itself on--then it starts raising the screen voltage until the rheostat maxes out. With inadequate drive, it could ne...
by TPT
Wed Mar 13, 2013 7:42 pm
Forum: FM Radio
Topic: Harris HT10
Replies: 4
Views: 2097

Harris HT10

Poor abused transmitter--sat for years at the base of a tall tower with no ground. Anyway, after replacing tube socket, bleeders that started smoking, plate contactor, losing an IPA, repairing the IPA regulator with it's $57 three pin regulator, having the IPA vanish in Reno (we think there is still...
by TPT
Sun Mar 10, 2013 7:57 am
Forum: TV Engineering
Topic: VHF-Low
Replies: 4
Views: 1389

Re: VHF-Low

#2 (above) hits the nail on the head. The main purpose of a TV transmitter anymore is to create a circle for must-carry. You don't really need to transmit on that transmitter--the fiber optic reaches the 95% of your audience watching on cable.
by TPT
Sun Mar 10, 2013 7:53 am
Forum: Radio Automation Systems
Topic: Simian Glitches
Replies: 7
Views: 4756

Re: Simian Glitches

Have three Simian systems on air--most of our problems come from Dial Global goofiness. Two of the systems are on satellite fed stations, one on a music station, with large hard drive & music library.

We defrag the hard drive fairly frequently, which seems to keep the systems happy
by TPT
Thu Mar 07, 2013 6:41 am
Forum: FM Radio
Topic: What type of contours?
Replies: 12
Views: 2699

Re: What type of contours?

Just did a frequency move for a college LPFM last year. When they applied for their original channel, more than ten years ago, that channel could not be used for a commercial channel. After they were on for about a year, a first adjacent station moved farther away, opening up an allocation near them...