Search found 92 matches

by COMMENG
Tue Oct 10, 2017 3:15 pm
Forum: AM Radio
Topic: OMNIA.7AM
Replies: 10
Views: 838

Re: OMNIA.7AM

We ordered one for a 1kW station and are running with a loaner Omnia.7 AM right now. We are still tweaking for the sound we want. Working with the Intermediate Level tweaks right now. Lots of customization available.

BTW, has anyone read the Specifications sheets for this unit? :D

COMMENG
by COMMENG
Wed Sep 27, 2017 1:58 pm
Forum: AM Radio
Topic: DX-50 works as speaker
Replies: 9
Views: 834

Re: DX-50 works as speaker

OK, guys, here's the skinny: The output of the variable cap connects to the tank coil ( why do they call it a "tank circuit"? ) via bolted tubing. At full power this point would arc with modulation. I noticed the bolt was literally red hot at 10 kW when I walked int the transmitter room before turn...
by COMMENG
Wed Sep 27, 2017 12:46 pm
Forum: Everything else
Topic: Parts
Replies: 0
Views: 108

Parts

I am not sure if this is the proper Forum but occasionally we see BE's needing parts for various transmitters, bot FM and AM.

A source that seems to have a large inventory of parts for older transmitters, ATU's, etc. is Dennis:

signalsradio.wordpress.com


COMMENG
by COMMENG
Tue Sep 26, 2017 1:35 pm
Forum: Everything else
Topic: FUNCTION GENERATOR
Replies: 2
Views: 158

Re: FUNCTION GENERATOR

I have a circuit that converts those low impedance unbalanced outputs to balanced ports.

Let me know if this interests you.


COMMENG
by COMMENG
Tue Sep 26, 2017 1:28 pm
Forum: FM Radio
Topic: Tower needed
Replies: 3
Views: 321

Re: Tower needed

I would contact this Group: https://natehome.com/ and find out which erector company would be closest to your location. The tower company engineer helps you with permitting, siting, FAA regulations, environmental impact statements, FCC regulations, material procurement, etc. The last time I had towe...
by COMMENG
Mon Sep 18, 2017 8:42 am
Forum: FCC Discussion
Topic: OET: OFFICE OF ENGINEERING AND TECHNOLOGY ANNOUNCES TECHNOLOGICAL ADVISORY COUNCIL (TAC) TECHNICAL INQUIRY INTO REFORM.
Replies: 0
Views: 124

OET: OFFICE OF ENGINEERING AND TECHNOLOGY ANNOUNCES TECHNOLOGICAL ADVISORY COUNCIL (TAC) TECHNICAL INQUIRY INTO REFORM.

"The FCC’s Technological Advisory Council (TAC), an advisory group to the FCC operating under the Federal Advisory Committee Act, is investigating FCC technical regulations and the processes by which they are developed to determine if increased efficiency and decreased regulatory burden can be reali...
by COMMENG
Mon Sep 11, 2017 10:51 am
Forum: FM Radio
Topic: New member - LPFM transmitter recommendations
Replies: 31
Views: 1450

Re: New member - LPFM transmitter recommendations

We have had good luck with the analog FM 250C from BE in a number of stations.

http://www.bdcast.com/information-cente ... ifications

We like to homebrew our own audio chain so we are not interested in internal audio processors.


COMMENG
by COMMENG
Wed Sep 06, 2017 9:10 pm
Forum: Digital Television
Topic: PCR Drift, how does it happen?
Replies: 1
Views: 252

Re: PCR Drift, how does it happen?

These might help: http://pixelmetrix.com/datasheets/AppNote/AN101%20PCR%20Jitter.pdf https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_application/application_notes/7bm55/7BM55_0E.pdf https://www.tek.com/document/technical-brief/laymans-guide-pcr-measurements http://www.tvtechnology.com/media-system...
by COMMENG
Tue Sep 05, 2017 7:38 am
Forum: AM Radio
Topic: DX-50 works as speaker
Replies: 9
Views: 834

Re: DX-50 works as speaker

I would shut the transmitter down and check two things:
1) the internal arc gap for dust, dirt, gap, etc.
2) the power combiner mother board(s) for dark spots and cracked toroids along the secondary rail rod.

COMMENG
by COMMENG
Tue Aug 08, 2017 12:08 pm
Forum: FM Radio
Topic: Tube question for the experts
Replies: 3
Views: 333

Re: Tube question for the experts

Here are some comparative tube Specifications:

http://www.g8wrb.org/triodes/


COMMENG
by COMMENG
Fri Jun 09, 2017 10:36 am
Forum: FM Radio
Topic: FM transmitter causing significant hum in surround components
Replies: 9
Views: 681

Re: FM transmitter causing significant hum in surround components

Hi I am assembling a project and am having a problem with the FM transmitter. When I connect the transmitter (power, signal and antenna) all of the other audio output components acquire a significant hum. Also, the transmitters signal (at a receiver) is almost solely the same hum. The hum is presen...
by COMMENG
Fri May 26, 2017 2:16 pm
Forum: Ask the Engineers
Topic: A real head-scratcher
Replies: 7
Views: 745

Re: A real head-scratcher

Well, here is what we know so far: The CRO is an AEG/Telefunken 140mm (diagonal measurement) scope tube. " D " is single trace, direct view, " GH " is a P31 screen phosphor; 521006 is the neck connection pin out configuration (not common), and "390" is an internal series designation which some belie...
by COMMENG
Thu May 18, 2017 3:44 pm
Forum: Ask the Engineers
Topic: A real head-scratcher
Replies: 7
Views: 745

Re: A real head-scratcher

What is the CRT's industry tube number?


COMMENG
by COMMENG
Wed May 17, 2017 2:09 pm
Forum: Ask the Engineers
Topic: A real head-scratcher
Replies: 7
Views: 745

Re: A real head-scratcher

It sounds as if the Character Generator Z-axis output isn't properly modulating the cathode. Somewhere between the Processor Board's Character Generator output and the Scope Amplifier board there should be an ORing function circuit that ORs the character generator output with other signals to modula...