Blonder Tongue agile modulator settings

[bandersen]

I just picked up a Blonder Tongue AM60-550B without a manual

Can someone help me out with the front panel settings and rear connecors ?

I think the output channel is set using a little binary math. Channel 5 would be 0000 0101 - right?

How about those switches to the left? Should I use STD or BROADCAST if I'd like to transmit to my vintage TVs?

Finally, do I need to do anything with the jacks and screw terminals in the middle of the back? I have a different, older model that has a short coax connecting the IF IN to IF OUT. Do I need that ?

Thanks!

[Phil Nelson]

There is a little pull-out card under "Channel Selector" that gives the DIP switch settings. At least, there is on my AM60-550B. If yours is missing, let me know -- I can take a digital photo and post it.

I didn't touch anything in the back. I do have the short jumper coax cable.

Anything seems to work as an antenna -- rabbit ears, a length of wire. Today I tested mine by walking outdoors with my Panasonic Travelvision handheld TV. The signal was perfect about 100 feet from the house. Around 200 feet outside, the signal got snowy but was still watchable.

Phil Nelson

[bandersen]

Hi Phil,

Nope, I don't have a pull-out card. I'd love a photo.

I couldn't find a decent piece of coax so I just used a little bit of wire to jumper that IF IN/OUT.
Bingo I'm broadcasting

Range seems good, but the signal is noisy. I'm hoping that due to my crude hookup. I'll keep hunting for a sort length of coax with the right connectors.

[Phil Nelson]

Here's a photo of the card.

http://antiqueradio.org/art/temp/BTCard.jpg

Peering back at your photo, it looks like I have an extra set of DIP switches. I believe the 550 in the model number means that mine can reach higher frequencies than the 450. If I were designing this stuff, I'd make the two models compatible so that the same settings would work for lower frequencies that they share. But maybe that's expecting too much.

I haven't tried looking for an owner's manual. Some companies put all of their manuals online.

Phil

[bandersen]

Thanks for the photo. Strange - mine is actually a 550 too.

[Tim]

Here are the switch settings from the Blonder-Tongue website:

http://www.blondertongue.com/switch-...ngs_StdIRC.pdf

[Phil Nelson]

Turns out that mine is a 550A, not 550B. No idea whether that makes a difference.

I couldn't resist writing a little article about my transmitter setup.

http://antiqueradio.org/HomeTVTransmitter.htm

Written for more of a lay audience, as most of my articles are. Anyhow, in it you'll find a better scan of the DIP switch chart.

Have fun!

Phil Nelson

[bandersen]

Perfect, just what I needed

[RDusel]

Thanks for the excellent info gentleman, I'm going to set up a similar system at home and at my mother's house where it is difficult to run hard lines.
Rob

[zenithfan1]

Originally Posted by RDusel

Thanks for the excellent info gentleman, I'm going to set up a similar system at home and at my mother's house where it is difficult to run hard lines.
Rob

It's a great way to go, mine reaches a block radius around my house. I wonder if any neighbors have caught on?

[jr_tech]

I would love to set up a system like this to supply video signals to sets in my "tv room" as well as portables around the house... but is it legal?

"Unlicensed broadcasts on the TV broadcast bands are prohibited, except for certain medical telemetry devices. 87.5 to 88.0 MHz is considered part of the VHF TV band (channel 6 audio is on 87.75), though it shows up on most FM tuners. For TV, 15.241 and 15.242 deal with high VHF (channels 7 to 13), 15.242 also deals with UHF."

From:

http://en.wikipedia.org/wiki/Title_47_CFR_Part_15

I believe the 100 milliwatt rule only applies to transmitters in the AM band, with very restricted antenna length.

If I set up such a system, will I be a Pirate?

jr

[zenithfan1]

Ahoy mateys! Arrrrrrg! Be a pirate with the rest of us I don't think it will travel far enough to bother anyone. Although, it does try to interfere with some of my analog cable channels. Ghost images of my transmissions show up like the old days when two analog stations would fight back and forth on skip days with the herringbone lines ect. I remember when I could sometimes pick up two channels on one station just by moving the antenna.

[jeyurkon]

Originally Posted by jr_tech

I would love to set up a system like this to supply video signals to sets in my "tv room" as well as portables around the house... but is it legal?

"Unlicensed broadcasts on the TV broadcast bands are prohibited, except for certain medical telemetry devices. 87.5 to 88.0 MHz is considered part of the VHF TV band (channel 6 audio is on 87.75), though it shows up on most FM tuners. For TV, 15.241 and 15.242 deal with high VHF (channels 7 to 13), 15.242 also deals with UHF."

From:

http://en.wikipedia.org/wiki/Title_47_CFR_Part_15

I believe the 100 milliwatt rule only applies to transmitters in the AM band, with very restricted antenna length.

If I set up such a system, will I be a Pirate?

jr

Actually I think you can be legal. But the requirements are complex. They do allow intentional transmission these frequencies.

Start reading this about halfway down and continue to unlicensed Part 15 bands. It seems to be legal. http://www.arrl.org/tis/info/part15.html But I think even a lawyer would be confused.

John

[jr_tech]

"Ahoy mateys! Arrrrrrg! Be a pirate with the rest of us"

I guess so... I can't really figure out what is legal

I have a parrot to put on my shoulder, and one "piece o eight", but no eye patch or peg leg.

jr

[Adam]

I just got an AM 40-450, and noticed that if you set it to the highest few channels, you can get on the low end of the uhf band with these too. The highest channel I have 78 corresponds to about channel 25 on the uhf dial.