Search found 692 matches

by TPT
Tue Jun 04, 2013 5:30 am
Forum: Ask the Engineers
Topic: antenna transmitter backup?
Replies: 9
Views: 2076

Re: antenna transmitter backup?

If you pull up Form 301 on the FCC web site there is a worksheet to determine if your proposed installation would create an RF hazard. With losses in the coaxial cable you have would have less than a kilowatt radiated from the vertical antenna, a circularly polarized antenna would have an ERP of les...
by TPT
Sun Jun 02, 2013 3:48 pm
Forum: Ask the Engineers
Topic: Harris FM3.5K Hobbs meter
Replies: 22
Views: 3425

Re: Harris FM3.5K Hobbs meter

After all that work he deserves a reward.... :D
by TPT
Mon May 27, 2013 6:04 am
Forum: Ask the Engineers
Topic: Starguide question
Replies: 1
Views: 650

Re: Starguide question

I suppose you could keep one just to power the LNB...but it's easier to get an active splitter. Between two stations at my one studio I have 5 different receivers looking at AMC-8 (or whatever it is called now)--2 Wegener I-pumps, Premier XDS, Citadel XDS, and a Starguide for Steelers. Having the ac...
by TPT
Wed May 22, 2013 5:14 am
Forum: FM Radio
Topic: Can Door Knob Capacitors be repaired?
Replies: 6
Views: 1380

Re: Can Door Knob Capacitors be repaired?

The question is why did it come apart? In other words, if you push it back together, wouldn't these same forces (thermal expansion and compression) just cause it to open up again?

Best to just pitch it.
by TPT
Sat May 18, 2013 5:09 pm
Forum: Ask the Engineers
Topic: Cband interference
Replies: 7
Views: 2532

Re: Cband interference

http://www.microwavefilter.com/ 2 types: The "AWACS" filter that hangs on the front of the LNB; and tuned filters to notch out specific interference. Military airborne radar systems operate just above the C-band transponder range. One way to tell you are being chewed up by an AWACS signal is that it...
by TPT
Sat May 18, 2013 7:02 am
Forum: FM Radio
Topic: Sibilance
Replies: 2
Views: 3861

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: 2532

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 be v...
by TPT
Tue May 07, 2013 5:00 pm
Forum: AM Radio
Topic: PSRA, PSSA on FCC site
Replies: 15
Views: 2277

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: 2776

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 Cleve...
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: 2584

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: 1065

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: 1018

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: 1840

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: 1840

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: 1570

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...