Search found 3368 matches

by Deep Thought
Mon Nov 12, 2018 2:37 pm
Forum: AM Radio
Topic: ATU rebuild
Replies: 20
Views: 518

Re: ATU rebuild

Here you go. I ran it twice, once with a base impedance close to what the measured data shows and once with the theoretical base impedance. You can match either with the same components. The current ratings need to be multiplied by 1.6 and the voltage ratings need to be multiplied by 6.0 to account ...
by Deep Thought
Mon Nov 12, 2018 8:30 am
Forum: AM Radio
Topic: ATU rebuild
Replies: 20
Views: 518

Re: ATU rebuild

What is the transmission line length? I can take that into account when adjusting the network for best bandwidth at the transmitter end.
by Deep Thought
Sat Nov 10, 2018 2:54 pm
Forum: Broadcast Engineering News
Topic: Tiger Mountain (WA) master antenna catches on fire
Replies: 8
Views: 180

Re: Tiger Mountain (WA) master antenna catches on fire

Looked to me like a radome fire...the top few seem intact. However they don't just go up on their own so something lower got damn hot.
by Deep Thought
Thu Nov 08, 2018 8:24 pm
Forum: AM Radio
Topic: ATU rebuild
Replies: 20
Views: 518

Re: ATU rebuild

I'll accept either a whine or a beg. No need to go overboard. :mrgreen:

If you give me a description of the tower and what is on it, I can model it and get pretty close to the right phase shift for optimum bandwidth without having to do a full sweep.
by Deep Thought
Wed Nov 07, 2018 10:34 am
Forum: AM Radio
Topic: ATU rebuild
Replies: 20
Views: 518

Re: ATU rebuild

DO NOT--repeat--DO NOT try to do this with a "single coil" network. It will be unstable as hell, almost impossible to tune due to the stray reactances and cross coupling between the turns on the coil, and will have shit for bandwidth. I will be happy to send you a proper design for free just to save...
by Deep Thought
Sat Nov 03, 2018 10:54 pm
Forum: Everything else
Topic: Wireless Mics and the Repack
Replies: 2
Views: 108

Re: Wireless Mics and the Repack

grich wrote:
Sat Nov 03, 2018 9:56 pm
We've already replaced equipment that operated above channel 36, right? :wink:
I'm sure T-Mo won't mind sharing... :mrgreen:
by Deep Thought
Sat Nov 03, 2018 10:52 pm
Forum: FCC Discussion
Topic: Knife edge limits for § 15.221 Operation in the band 525-1705 kHz.
Replies: 2
Views: 182

Re: Knife edge limits for § 15.221 Operation in the band 525-1705 kHz.

The perimeter is the outermost property line. As a practical matter, unless you are going to deploy multiple transmitters the limit will be imposed at the point on that perimeter closest to the antenna.
by Deep Thought
Thu Oct 18, 2018 8:49 am
Forum: AM Radio
Topic: Gates 5 rebuild
Replies: 6
Views: 548

Re: Gates 5 rebuild

Otherwise, the basics apply to this rig... keep it clean, keep it cool, visit it once in a while. They also really *really* don't like open delta power feeds. One client was replacing fuses and FETs on a monthly basis until they installed a delta-to-wye transformer and haven't had a major problem s...
by Deep Thought
Wed Oct 10, 2018 9:16 am
Forum: FCC Discussion
Topic: Does the FCC keep track somewhere of subchannels?
Replies: 3
Views: 336

Re: Does the FCC keep track somewhere of subchannels?

The FCC only tracks stations running in a digital mode (assuming you're talking about FM) and not how many or what is on the subchannels.

Digital TV is licensed as such, but the FCC does not track the 'dot' channels deployment.
by Deep Thought
Sat Oct 06, 2018 12:07 am
Forum: Everything else
Topic: RING MY BELL
Replies: 21
Views: 456

Re: RING MY BELL

It was the ones used for the phones, I believe, so although it was very close to the two-tone EAS alert it wasn’t the actual thing. So I wasn’t sure if that was a violation, but affiliates sure did. Heard of one that pulled all newscasts for the rest of the day until they got assurances. Anything t...
by Deep Thought
Tue Oct 02, 2018 11:57 am
Forum: Ask the Engineers
Topic: Dead Relio Revived
Replies: 13
Views: 651

Re: Dead Relio Revived

Sometimes it helps to pre-heat the PCB (if possible) before attempting to desolder these components. I have used my heat gun to warm up the bottom side of the PC board to just hot enough to hurt a bit when touched with a bare finger and then attacked the pad with a desoldering iron. It makes things...
by Deep Thought
Wed Sep 19, 2018 9:37 am
Forum: AM Radio
Topic: Retune Harris DX10
Replies: 7
Views: 390

Re: Retune Harris DX10

Data point: As of about two months ago Nautel was selling their current-production NX-10 for about $42,000 "street price". This box includes MDCL as a standard feature which can meaningfully reduce your electric bill. While that is probably considerably more than you have invested in the DX-10 it ma...
by Deep Thought
Tue Sep 18, 2018 5:56 pm
Forum: AM Radio
Topic: Retune Harris DX10
Replies: 7
Views: 390

Re: Retune Harris DX10

What frequency is it on and what frequency do you need it tuned to?

It is possible to do it but you'll need the proper test equipment and possibly some replacement parts.
by Deep Thought
Tue Sep 18, 2018 11:30 am
Forum: AM Radio
Topic: Crystal alternative
Replies: 17
Views: 975

Re: Crystal alternative

That said, if you're using something like what I'm reading the ProgRock to be, might be easier just to run it at your carrier frequency, use it as the source for a differential amplifier with a 15V rail and jumper the transmitter to use the external RF drive source. Easy enough to do and removes an...
by Deep Thought
Fri Sep 14, 2018 12:52 pm
Forum: AM Radio
Topic: Crystal alternative
Replies: 17
Views: 975

Re: Crystal alternative

Micheal Paton from Baton Rouge, La. had a device for some of the Harris AM transmitters. I think he said it could be set via dip switch to output a frequency of .5 to 5Mhz. I saw the board he had at the Alabama Broadcasters Association convention and it looked professionally made and the price wasn...