Search found 814 matches

by TPT
Thu Jan 24, 2019 7:40 am
Forum: FM Radio
Topic: HT-10 APC issues
Replies: 12
Views: 652

Re: HT-10 APC issues

Believe most of those IPA's in the HT-10 are repairable by Silicon Valley Amplifier--if you are prepared to wait. Took almost a year to get one fixed for a transmitter I have to deal with. While it was out we drove the transmitter with a Nautel V-1 (not VS series). Match was touchy, but we were able...
by TPT
Wed Jan 23, 2019 6:14 pm
Forum: FM Radio
Topic: HT-10 APC issues
Replies: 12
Views: 652

Re: HT-10 APC issues

What kind of exciter? Digit exciters were shipped with some of the HT-10's
There are various problems that can develop with the digit exciters with age, including spurs that might show up as AM noise. Usual cure is to recap the exciter.
by TPT
Sun Jan 20, 2019 5:14 pm
Forum: FM Radio
Topic: Harris HT-10FM freq change
Replies: 5
Views: 262

Re: Harris HT-10FM freq change

Having one of these to take care of--my immediate question is:

WHY!!!!

You will probably have to fuss a great deal shifting around the "deck"--metal plate attached to the final--to get the darn thing making power without oscillating.
by TPT
Wed Jan 16, 2019 7:44 am
Forum: AM Radio
Topic: EZ Kleen Filters
Replies: 3
Views: 333

Re: EZ Kleen Filters

Interesting. The NV-LT series uses conventional paper/fiberglass (?) filters. A little oddball--2" deep--not something carried by your local big box hardware supplier--but available through Amazon. At least that is better than the Trane furnace at my transmitter site. Goes into a tray that is interl...
by TPT
Thu Jan 10, 2019 9:13 am
Forum: Ask the Engineers
Topic: AMP connector info needed AudioArts console
Replies: 9
Views: 265

Re: AMP connector info needed AudioArts console

These are rectangular plugs--the 15 pin about 1" by 1/2" with a 3X5 pin arrangement, 3X4 in the case of the 12 pin connectors used in the R-60 console. The plug is about 3/4" high. The plugs have "wings" on the long sides that lock with the headers on the console motherboard. The headers have pins, ...
by TPT
Wed Jan 09, 2019 8:39 pm
Forum: Ask the Engineers
Topic: AMP connector info needed AudioArts console
Replies: 9
Views: 265

Re: AMP connector info needed AudioArts console

Eureka! I knew I had this somewhere. Yes, appears these things are still available. The R-60 uses 12 pin shells, the Auditronics 2500 (I have several of these in use) --use 15 pin shells. The "male" pins are on the motherboard headers, the "female" pins are used in the plugs. Here are the part numbe...
by TPT
Wed Jan 09, 2019 8:22 pm
Forum: Ask the Engineers
Topic: AMP connector info needed AudioArts console
Replies: 9
Views: 265

Re: AMP connector info needed AudioArts console

Mouser used to have these shells and pins, but I can't find them on-line. May be obsolete. I may have a bag of pins with a Mouser number--will check tomorrow. I remember answering this same question on this board not long ago--but can't find it. Alternative may be to call Wheatstone & see if anyone ...
by TPT
Tue Jan 08, 2019 3:23 pm
Forum: Ask the Engineers
Topic: STRANGE COIL - UNUSUAL PROPAGATION?
Replies: 3
Views: 192

Re: STRANGE COIL - UNUSUAL PROPAGATION?

To elaborate further, 300 to 3000 hz is in the audio frequency range. Transmission facilities have been built in this range, but were not very efficient due to the length of a wavelength at these frequencies: (from Wikipedia article on extremely low frequency--ELF Rf transmission: "The US maintained...
by TPT
Fri Jan 04, 2019 10:12 pm
Forum: Radio Studio Engineering
Topic: Unit or circuit to properly convert stereo to mono for AM Tx is ?
Replies: 8
Views: 225

Re: Unit or circuit to properly convert stereo to mono for AM Tx is ?

On the Ebay stuff I automatically replaced the caps.
by TPT
Thu Jan 03, 2019 7:50 pm
Forum: Radio Studio Engineering
Topic: Unit or circuit to properly convert stereo to mono for AM Tx is ?
Replies: 8
Views: 225

Re: Unit or circuit to properly convert stereo to mono for AM Tx is ?

Another device is the Henry Engineering USDA 2x4 Utility Summing & Distribution Amplifier. Couple on E-Bay for various prices. Stereo in, either two separate stereo outputs or mono outputs. Not impressed by audio fidelity (I have a couple of these--use them to mix the outputs of our STORQ automation...
by TPT
Wed Jan 02, 2019 1:24 pm
Forum: FM Radio
Topic: Horizontal or vertical
Replies: 8
Views: 588

Re: Horizontal or vertical

Most listening nowadays is done in the car. Go to your local mall and do an informal survey of the car radio antennas....
by TPT
Mon Dec 31, 2018 5:03 pm
Forum: Ask the Engineers
Topic: STRANGE COIL - UNUSUAL PROPAGATION?
Replies: 3
Views: 192

Re: STRANGE COIL - UNUSUAL PROPAGATION?

Well, it might work as a power transformer, but not much good for anything above 60 hz. Put another way, shove enough RF into it, and it will radiate. Not very well or very far, but it will radiate. So will a dummy load, except the transmitter is less likely to either shut down or melt down. Wavelen...
by TPT
Tue Dec 11, 2018 10:46 am
Forum: FM Radio
Topic: High Reflected Power Puzzle
Replies: 33
Views: 1191

Re: High Reflected Power Puzzle

Had a similar problem in building a new LPFM. VS300, combination of flex line and regular 1/2". Everything looked good--but high VSWR. Tower climber (also a ham) asked--what frequency is this station on? Me: 96.3 He: The antenna is marked 93.1. If you could borrow another transmitter or even an exci...
by TPT
Tue Dec 04, 2018 6:55 pm
Forum: FM Radio
Topic: Horizontal or vertical
Replies: 8
Views: 588

Re: Horizontal or vertical

Look at the Scala HDCA-5CP/RM, which is a 5 element circularly-polarized yagi. There are two smaller models as well, all rated for 250 watts.
by TPT
Wed Nov 28, 2018 8:12 pm
Forum: Radio Automation Systems
Topic: Simian Automation Folder Architecture
Replies: 11
Views: 1059

Re: Simian Automation Folder Architecture

Just because you can do something doesn't mean you should.... Local cluster uses a server based automation system for all of the stations. Story around town that a fired employee got back in on a weekend and pulled the plug on the server.....no-one noticed until Monday morning! We mostly use refurb ...