w9wi wrote: ↑

Sun Jan 19, 2020 8:14 am

What do you all think the chances are the FCC will, in the next 3-5 years, allow AM stations to silence the AM signal & operate only on the translator(s)?

Zero. The LPFM fanatics will make sure of that.

There is a battery which is probably dead if it has been sitting around without power for years. IIRC it powers the internal time of day clock. The presets and firmware are in non-volatile flash memory but that has been known to be corrupted under certain conditions. Unfortunately it is not on a car...

I am debating with myself how much project work I am willing to do at my advanced age <g>... I got on a plane to sunny but rather chilly southern California last Thursday. I've spent these 7 days re-tuning one four tower DA-2 and running partial proof on it, completing a Method of Moments proof and...

How many bays?

Also: I had a BW 300 which was shipped with inoperative reflected power detection so I don't think I would trust that.

RGORJANCE wrote: ↑

Mon Dec 23, 2019 10:23 am

Hope everyone has a Merry Christmas and Happy New Year,,,,,,,,,and may your phone remain "Silent Night" every night.

Fossil

And the same to you up nort.

Another question that I thought of was.... What effect would the natural reactance of the tower have on the isolation coil as its j swings positive to negative as the bands change? Or does it matter? Aside from the general AM aspect of this discussion, I know that as many IP radios as I am deployin...

What is the base impedance at each frequency of interest? One rule of thumb is to design an isolation coil with at least 50 times the Z at the tower feedpoint, which means a short tower with a 20 ohm base impedance would require a +j1000 ohm coil, or around 88 μH at 1.8 MHz. Most of the commercial u...

Define "very close". If they are more than several dozen wavelengths from the antenna I doubt you'll notice anything.

At STL frequencies they become a fairly effective reflector so the 950 MHz anecdote doesn't surprise me.

COMMENG OK you win. I guess all that time I spent actually participating in real-world tests was just a mirage. However, you clearly have no idea what the hell you are talking about, to wit: "And while 64-QAM digital transmission is an interesting modulation mode and has been used as the modulation...

For example, MA3’s peak-to-average ratio is significantly higher than that of analog AM, so the transmitter’s power level meter may read inaccurately. Also, if the transmitter isn’t optimized for MA3 mode, the peak-to-average ratio may be reduced, and a different power level reading may result than...

What digical format are they proposing? The current HD IBOC or DRM or yet something new? It appears the Digital MA3 standard will use a 64-Quadrature Amplitude Modulation. This means the QAM is generated at a low level and amplified by Linear Amplifiers. ...As linear amplifiers are less efficient t...

One of my clients (WDGY, Hudson, WI) was a test bed station for the original MA3 testing in 2014. I had already installed the Nautel IBOC exciter and exporter, which was feeding a Nautel XR6 in hybrid mode. The only changed required to switch from hybrid MA1 to MA3 was a firmware update which Jeff W...

About f'n time.

rfn wrote: ↑

Mon Nov 11, 2019 10:00 am

And there is why I carry a phase-shifting XLR/XLR when doing work for stations using asymmetric modulation.

All that does is invert the audio. It does not address the underlying issue.