HFU HF Underground

Technical Topics => Part 15 AM and FM Station Operation => Topic started by: tybee on September 07, 2025, 0423 UTC

Title: Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm.
Post by: tybee on September 07, 2025, 0423 UTC
I saw this rack mount unit on eBay and am curious if it could be utilizes as only an AM carrier-current transmitter? I don't know anything about this thing, but could it be the "1310 nm" refers to the frequency for audio?
I personally have no need for such, but if turns out it could be used as such then I'm sure someone would be interested. It's $99 or best offer. There's numerous  pictures in the auction. To be clear, I'm not the seller, just saw it on ebay

Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm
https://www.ebay.com/itm/156451980138
(https://i.ebayimg.com/images/g/DIwAAOSw52xnCBXi/s-l1200.webp)

Item description from the seller
This sale is for a Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm. Item powers up and it's in good cosmetic condition. We are unable to test it for “full” functionality ourselves at our facility. There are some scratches and/or scuff marks on the item from normal use. It will also come with a power cord.

Item comes with a full 30-day warranty (US Only).
Title: Re: Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm.
Post by: europirate on September 07, 2025, 1937 UTC
It's a fibre-optic TV transmitter for the cable TV market - 1310nm (nano metres) refers to the wavelength of the light source (laser).
Title: Re: Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm.
Post by: tybee on September 07, 2025, 2008 UTC
Ok, that makes sense (I had no idea what the "nm" signified), but it's called a "VSB/AM", which Google tells me:

"VSB/AM" stands for Vestigial Sideband Amplitude Modulation, a technique that transmits one full sideband along with a small portion ("vestige") of the other sideband to save bandwidth while simplifying demodulation compared to single-sideband (SSB) modulation, and is notably used in digital TV broadcasting like the ATSC standard.

Yeah, well, that's over my head, and why I posed the question here. Since the unit is designed to pass an amplitude modulated signal, does that mean it could be easily modified to utilize as an AM carrier-current system?
Title: Re: Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm.
Post by: europirate on September 08, 2025, 0922 UTC
I can't see it being any use for anything useful, other than a nice 19" rack case to use for a new project ...  ;D
Title: Re: Emcore 2804TK-SCAP/12 CATV VSB/AM Transmitter 1310 nm. No, light...
Post by: ThaDood on September 08, 2025, 1630 UTC
Yeah... That's an interesting converter, to take NSTC video, to modulate it on Infra Red light, to then send on Fibre Optic link to like a CATV Head-End facility. The TV station that I worked at did this to send clean A/V signal from our studios to Time Warner Cable, at the time. Except, that unit was twice the size of a pack of cigarettes. If, you had a means to de-MOD that light FREQ, through Fibre Optic Cable, then it would make for a nice STL to a transmitter somewhere. other-wise??? The case, and maybe the built-in power supply, would make for better use.