Search found 39 matches

by LowBand
Sun Nov 24, 2013 2:35 am
Forum: AM Radio
Topic: EPMs / Spectrums for AM Stereo
Replies: 17
Views: 3706

Re: EPMs / Spectrums for AM Stereo

Although while I was setting up the IBOC equipment at WDGY this week I noticed that the Nautel AM IBOC exciter has a C-QUAM mode. Was tempted to switch it to that and see what happened. :mrgreen:
I double dare you to switch it! :D
by LowBand
Mon Nov 11, 2013 12:03 am
Forum: AM Radio
Topic: Calculating Gain of an AM Directional?
Replies: 4
Views: 1226

Re: Calculating Gain of an AM Directional?

Hello Is there an easy formula for calculating the gain of an AM directional array? Any help would be appreciated. I have done web searches and text book reviews and not found any reference. Thank You jje64 A number of texts come to mind that contain pattern equations for directionals: 1. The Compl...
by LowBand
Sun Nov 10, 2013 6:51 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

Asymmetry by definition is "distortion." It generally indicates that there is a considerable amount of even order harmonic energy... Keep in mind that forced asymmetry is a completely different animal... Most male voices contain a lot of asymmetry, but I wouldn't say they are "full of distortion," ...
by LowBand
Thu Nov 07, 2013 7:34 pm
Forum: Ask the Engineers
Topic: AM Air Monitor?
Replies: 2
Views: 764

Re: AM Air Monitor?

This one has internal speakers and a decent sound in a retro look. Two of our stations have these.

http://www.fullcompass.com/product/453186.html

Phil
by LowBand
Mon Oct 14, 2013 7:15 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

Playing around with my Inovonics 235 which was modified to my taste at the factory by Jim Wood, keep the peak processing (clipping) down. Use EQ to bring up a louder sound without distortion. Yes, I realize that Omnia and Orban are louder boxes, but on AM, in my opinion, there is a point not that t...
by LowBand
Mon Oct 14, 2013 6:53 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

From: Modulation, Overmodulation, and Occupied Bandwidth: Recommendations for the AM Broadcast Industry An AM Improvement Report from the National Association of Broadcasters September 11, 1986 Harrison J. The primary cause of splatter is excessive high frequency content in modulating audio. This is...
by LowBand
Mon Sep 16, 2013 7:12 pm
Forum: AM Radio
Topic: Improvements in AM Broadcast and Commissioner Pai
Replies: 14
Views: 3489

Improvements in AM Broadcast and Commissioner Pai

Interesting Article in NYT:

http://www.nytimes.com/2013/09/09/us/a- ... tatic.html


If you would like to send comments regarding AM improvements they may be addressed to

http://www.fcc.gov/leadership/ajit-pai-mail

Phil
by LowBand
Mon Sep 16, 2013 12:22 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

Pioneer,

So are you working on a low Power ClassE broadcast or Ham radio transmitter?

Phil
by LowBand
Sun Sep 01, 2013 1:02 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

I am not having that problem.
The OP never said he was having a problem nor identified one.

He was asking a question about the theory of operation.

Phil
by LowBand
Fri Aug 30, 2013 7:55 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

If I read this right, it means that there's nothing there to limit negative peaks from exceeding 100%. This doesn't seem right - after all, program levels in an actual control room are all over the place - I've seen VU meters regularly pegged by indiscriminate jocks. The 235 will allow asymmetrical...
by LowBand
Fri Aug 30, 2013 7:27 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16825

Re: Asymmetrical modulation

Here I design a small medium wave broadcast transmitter, it has a peak output power off 320 watt approximately (pep). Normaly the pulse duration duty cycle is 45% with this kind off transmitters. I assume this is a ClassE transmitter by your description. The bottom traces still appear to be symmetr...
by LowBand
Wed Aug 21, 2013 3:00 pm
Forum: AM Radio
Topic: Armstrong 500 watt AM output network board
Replies: 7
Views: 2097

Re: Armstrong 500 watt AM output network board

Turns out the PA module is fried anyway, so it didn't matter. Evidently they can't get hold of the "AM guy" most of the time and he refuses to take support calls. Just what you like in a transmitter manufacturer. I'm pretty sure the NOAA weather radio contract is all that is keeping these guys aliv...
by LowBand
Tue Aug 06, 2013 10:55 pm
Forum: AM Radio
Topic: combining into a folded monopole
Replies: 6
Views: 1749

Re: combining into a folded monopole

You could try contacting the LBA company: http://www.lbagroup.com/products/tunipole-and-combipole-antenna-systems I am sure some NEC modeling would have to done on a three-legged SS tower. http://www.antennex.com/w4rnl/col0807/amod114.html Also, Kintronics: http://www.kintronic.com/products/standar...
by LowBand
Tue Aug 06, 2013 10:13 pm
Forum: AM Radio
Topic: combining into a folded monopole
Replies: 6
Views: 1749

Re: combining into a folded monopole

You could try contacting the LBA company: http://www.lbagroup.com/products/tunipole-and-combipole-antenna-systems I am sure some NEC modeling would have to done on a three-legged SS tower. Paper by Raines: http://www.rainesengineering.com/articles/SimpleFormulasFoldedAntennas.pdf Paper by Mullaney: ...