900 mhz ISM Band HDTV

Check:
http://www.qsl.net/tri-atv/
http://www.amateurlogic.tv/blog/

I don't know of any hams broadcasting D-ATV (digital amateur tv). I do know 2.4 gHz is the more likely band for Part 15, which can use Part 15 off-the-shelf extenders, intended mostly for sending wireless A/V signals to other rooms in your house, or neighboring buildings, but they don't have much range. Technician-class licensed hams can do Amateur TV (ATV) on the 70cm (420mHz) band, with much more range, and there is also SST V (slow-scan TV) ... but remember it's amateur band stuff ... appropriate restrictions apply. You can broadcast ATV along with standard 2M voice, meaning you can have meetings where others can chime in via 2M and/or repeaters with voice.

Could also be streamed to the Internet, of course, with
Ustream http://www.ustream.tv/
... or ...
Veetle http://veetle.com/

Don't throw away your old TV if you want to play with ATV.

Or hang on to those component tuners and feed a flat screen with it.

Just curious, why would anyone want to transmit ham HD tv for? I mean do they allow you to put on a costume and act out a play worthy of high definition? Choose your op mode, 720p or 1080p. Wow I can see every wrinkle and scar and pit in them there faces! Har har!

Well...maybe there is something better on that than the 300 channels of useless HDTV.

RFB

There are lots of options for SD TV on the 900 Mhz band.

Older video senders used to use this band (some newer wireless speakers still use it). These are fairly low power units that are FCC certified.

A number of TV transmitters from China have recently shown up on e-bay. Some of the ones with 16 channels or more advertise that they cover 900-1200+ Mhz. Of course, they aren't FCC certified. Their quality is unknown.

And there is still some amateur equipment around that can do that band. I myself have an older Wyman Research ATV transmitter that will do 900 Mhz, but it's buried in storage somewhere. I don't think there's much amateur radio ATV these days, when you can skype or do facetime from anywhere.

I do know that there are some amateurs working on HD ATV, just haven't seen anything in the field yet. Then again, haven't looked all that hard.

As a ham - when I was a kid -
I wanted to do ham TV REAL BAD
with a friend who lived near by.

There was a guy down the street
who let me have an old TV that was sitting in
his garage. I carried it all the
way home only to find that - somehow -
even though the front of the TV looked
completely normal - there was nothing
inside the TV except for the picture tube.
That's as far as I got.

I have one of those old 900 MHz TV transmitters
and receive converters. If you get the picture
tuned in on the receiving end you get no sound.
If you get the sound tuned in you get no picture.
I did use it to help me set up an over the air
HDTV antenna and converter in my attic. I used
the unit to transmit the TV picture back up to
the attic so I could see what was going on. That
worked out really well.

At age 58, today - I look terrible. I usually
look better than this, but not today. Nobody's
gonna transmit a TV picture of me.

I always wanted to get a radio controlled car,
and put a ham TV transmitter/camera on it -
drive the car by remote control and watch it
on TV. Why? I have no idea.

We had an awesome ham radio ATV repeater here
about 20 or 25 years ago. But I wasn't equipped
for it. The fun was in the silliness of the
guy who ran it. His crazy sense of humor made
it worth watching.

Bruce, DRS2

I fed standard NTSC video into an old Lafeyette RF signal generator. It had a connection for external modulation.

Set the RF frequency to TV channel 2 and actually got a picture on the TV. Granted it was pretty soft as the modulation input was for audio but hey, I got a picture.

Of course the modulated signal was not vestigial (one sideband) and no FM audio subcarrier but it was an interesting experiment.

And having anything from Lafayette radio
(I miss them) is neat. I have an old Lafayette
VHF/UHF monitor receiver.

When I was about 11, practically the whole
neighborhood of kids got Radio Shack Space
Patrol walkie talkies at the same time. This was
about 1966.

Kids were all running around the houses TRYING to
contact each other. (Ha ha ha - those walkie
talkies were so terrible.) Then somebody noticed you
could see the audio signal on TV channel 2 -
which was the second harmonic of, well, you
know. Not only could you see the transmitted
signals on the TV, but those regen receivers in
those primitive walkie talkies put out RF also.
THAT RF would appear on the TV screen too, in
a weird swooping pattern that I can't quite describe. (Or
remember.) (There's no channel 2 in Hartford.)

I started TV DXing at age 7. In Hartford I
would get channels from the surrounding states.

I really miss TV dxing. The days of getting an
E-skip NTSC channel 2 or 5 or 6 from across the country
on a black and white TV in the house with rabbit
ears sure are over. (Sigh.) Back when NTSC channel 3
was running - a few years ago - there was no
way you could get E-skip on channel 4 (here) - 4 was blocked out.
2 was no problem. I don't know why.

There are TV DXers in the nearby area that have seen NTSC TV skip
from Mexico, Cuba and Venezuela in the last few years. But
these guys have sophisticated receiving set-ups.

I had an article about TV E-skip (and E-skip in general)
from a 1958 QST that was in my stack of "favorite radio
and electronics papers and notes and general odds and
ends." I haven't seen it lately. It was from legendary
TV DXer Bob Cooper (?) He had logged E-skip all the
was up to TV channel 13, if I'm correct, back in the
1950s. I always wanted to be one of the guys who saw
upper VHF band (channels 7 - 13) TV DX E-skip, but
it was not to be.

Bruce, DRS2

It was the very first NTSC TV E-skip I
ever saw, and it was the last, also!

In the summer of 1970 I saw channel
2 from Orlando, FL in Connecticut between
noon and 1:PM local time. I had never seen
TV E-skip until then.

About 40 years later, when the analogs were
all being turned off, I took a TV and a channel
2 receiving dipole up to my attic, and there it
was again, via E-skip, hanging in there for
several hours fading up and down between
3 and 5 PM afternoon local time - WESH channel 2 -
doing their nightlite service.

Same Bat-time, same Bat-Channel. What an odd
coincidence.

Bruce, DRS2

I was probably 12 or 13. I had an old 1984 RCA color TV. It was one that had one tuning knob. VHF channels 2-13 and 5 UHF channels that you had to fine tune for your area using 5 knobs behind the control cover. My 5 channels were 19, 45, 48, 64, and one blank channel that I used for any other UHF channel I wanted to watch (16, 22, 25, 26, 38, 43, and 54 were also available in my area when analog existed). Apparently, there weren't many UHF channels in the 1980s. My antenna was a basic rabbit ear VHF antenna. I didn't purchase a decent antenna until 2008 (When I purchased my first ATSC digital tuner. Digital sucks here without a fancy amplified indoor antenna). On a Saturday morning, I was flipping through the VHF dial, and I picked up a signal from Indianapolis on channel 13. It was very clear for being from over 100 miles away and being received on a $3 antenna. The only interference I saw was wavy lines (probably bleed over from WKRC channel 12). I was mesmerized. Lol

About a year later, I was at my grandma's house in New Richmond. She gave me an ancient 1960's RCA Victor B&W console TV and a very nice indoor antenna. I kept it at her house because I had no room here. The TV was so old that it took over a minute for the tube to warm up. In fact, I first thought it was broken. I spent the night at her house one time, and experienced an awesome TV DX around 6:30 AM on a Saturday. I picked up WLEX-TV, Channel 18, from Lexington KY with a crystal clear picture. It was the clearest analog picture I have ever seen. It was too clear to be distant local reception. Lexington is about 85 miles from New Richmond, so even with a good indoor antenna, the picture would've been extremely snowy. It was amazing. Either that old RCA TV had an amazing tuner, or there was some crazy good E Skip.

Sadly, my cousin Jeremy (NOT my broadcast partner, a different Jeremy) moved in with my grandma a year later and gave my RCA TV and antenna to Goodwill when he cleaned out her spare room. I was so mad!!!!!!!!!!!!! That classic TV was probably worth a fortune.

It was TV DX that started my interest in radio. I was at the cottage in Ontario during the 1960s, about 100 miles north of Toronto - we had an old black & white TV with an antenna stuck in a tree. On Channel 2, one night in the dead of summer I was able to watch an entire program that originated in Texas. How and why that happened got me hooked.

TV DXing. Your stories have the same
astonishment in them that my stories
have.

How can this happen and why? And also,
when will it happen again, and will I
be there at the right time to witness it?

I also remember the TV tuners that had to
be preset with little knobs. I had some
TVs and VCRs that were like that. They
were peculiar things, but I liked them
for some reason.

Wonderful stuff.

Bruce, DRS2