Search found 541 matches

by Kelly
Sat Feb 15, 2020 4:32 pm
Forum: Digital Television
Topic: Cisco DCM D9900/D9901/D9902 (EOL)
Replies: 1
Views: 249

Re: Cisco DCM D9900/D9901/D9902 (EOL)

Even though EOL, some Cisco resellers will still have access to the O.S. library.
May have to shop around to resellers to find one that won't just try to sell you replacement hardware.
by Kelly
Sat Feb 15, 2020 4:29 pm
Forum: TV Engineering
Topic: TV Transmitter question
Replies: 1
Views: 221

Re: TV Transmitter question

Here's a link to what's left of their website: https://www.electronicconnectors.net/e-l-marsden-wireless-inc/ I believe Marsden imported and re-branded these transmitters from Chile. Remember seeing one at a site probably six years ago. Pretty sure it was used as a backup for an LPTV at the same sit...
by Kelly
Fri Jan 24, 2020 9:26 am
Forum: FM Radio
Topic: HD Portable Radio with split audio capability
Replies: 5
Views: 493

Re: HD Portable Radio with split audio capability

None that I've ever seen. Usually I'll take two portable radios to the TX site, one analog and one HD-capable. Fire them both up and see how far things are off.
by Kelly
Thu Jan 16, 2020 9:55 am
Forum: FM Radio
Topic: optimod 2300 boots to blank screen
Replies: 3
Views: 306

Re: optimod 2300 boots to blank screen

That sounds like it's not even booting-up. Like anything else, many of the failures like this are power supply-related. Might be a dead +5V supply.
by Kelly
Thu Jan 02, 2020 4:29 am
Forum: AM Radio
Topic: Gates 5--no audio
Replies: 28
Views: 1240

Re: Gates 5--no audio

Before I attempt surgery on the PDM geni board, could the audio be vanishing beyond this point? Another question--if I haul my old and very heavy scope up the hill and look at the output of the PDM geni baord, would I be able to see audio at this point, or just the 60 KHZ? If your PWM stopped, then...
by Kelly
Thu Dec 26, 2019 7:53 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

The Large Corporate Groups may have a few "throw away" medium wave stations that they could afford to play with Digital Modulation on. But I don't see them abandoning a revenue producing AM modulated station just to experiment, the profit margins on radio are a bit too thin for that. Hubbard did th...
by Kelly
Tue Dec 24, 2019 11:29 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

I thought we were going to keep this technical and not inject politics. Not sure where you see politics in my comment. Right Wing talk? Since Air America isn't on the radio, let alone any AM stations anymore, there is no Left Wing Talk that I'm aware of to balance out labeling the format. The label...
by Kelly
Sun Dec 22, 2019 3:47 pm
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

I don't know about the rest of you but I'm an Old Fart with reduced hearing. My belief is that most AM listeners are somewhat that same category. So having a "wide" audio response in this proposed AM Digital Mode isn't a necessity. Anything above 7.5K is wasted. I suspect that most self-described "...
by Kelly
Fri Dec 20, 2019 9:15 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

ncradioeng wrote:
Fri Dec 20, 2019 8:55 am
Does all-digital do stereo?
Yes it will. When the receiver first locks-on audio may be mono for a few seconds until enough bits are captured.
by Kelly
Fri Dec 20, 2019 8:14 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

So, depending on how the CODEC was set up, about 9.5 kHz to 14.25 kHz of analog audio can be encoded. COMMENG That sounds about right (pardon the pun). The claim is that AM MA3 digital would have about the same frequency response as analog FM, without the need for preemphasis/deemphasis. Considerin...
by Kelly
Wed Dec 04, 2019 5:22 pm
Forum: AM Radio
Topic: Harris DX-10 Fold Back Power Issue
Replies: 3
Views: 348

Re: Harris DX-10 Fold Back Power Issue

I have been called to work on a Harris DX-10 that is folding power back to 1,000 watts. We have checked the load presented by the tower which is correct. The Bandpass filter light is red on the transmitter after you pass about 2200 watts and it folds back the power to 1,000 watts. Everything in the...
by Kelly
Tue Dec 03, 2019 11:49 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

Apparently many of the nine test stations had problems meeting the Mask requirement so the FCC is asking for more input. In addition, " ...The NRSC has not tested or evaluated the MA3 mode, including the emissions mask, although the all-digital specifications are included in the NRSC-5 standard ......
by Kelly
Wed Nov 27, 2019 10:44 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

So with measuring power when operating MA3, just standard common point (directional) or base current Non-D is all one needs to maintain?
by Kelly
Tue Nov 26, 2019 3:32 pm
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

What people are saying in the DX community is there is probably a limited cohort of stations interested in all-digital. The really big stations (the KFABs and WBALs and KNBRs) have enough AM audience left that they're not willing to toss most of them out by going all-digital. The really small stati...
by Kelly
Tue Nov 26, 2019 5:06 am
Forum: AM Radio
Topic: AM Digital NPRM
Replies: 54
Views: 2380

Re: AM Digital NPRM

Its the same encoding/modulation as HD, just without the analog AM component. WWFD has been under an STA in this mode for a couple years. They've essentially found what we discovered back in the early days of testing HD on AM: That running in digital-only mode decreases the adjacent channel interfer...