I just received a used Blonder-Tongue AM 60-550B from an Ebay auction.
There is no manual or dip switch setting card. I have seen other posts where someone posted a pic of the switch settings, but they don't match what I have. My unit only has 8 DIP switches and I'm not sure how to set them. Through dial and error, I did get it to transmit only on channels 5 and 8 and the quality is very bad with a DVD player as input. There is a lot of buzzing noise and black horizontal lines in the picture. I wonder if I just got a bad unit ? Does anyone have the switch settings for this model ?
Thanks.

I did a lot of rummaging around on the Blonder Tongue web site and found a document showing the switch settings for several models. There are modulators that take an RF input and translate it to a different channel and there are models that take a standard video input and output RF on your choice of channels. The translators have double the number of switches compared to the straight modulators. The document I found covered both types. It took me a little while to figure out what is what on that document. It turns out that the switches specifying the output channel on the translators follow the same pattern as the switches specifying the output channel on the modulator.

Edit: I am sure that I kept a copy of that document, but it is getting late tonight. If you can not find it on the Blonder Tongue web site, I can try to dig it up tomorrow and post it.

I don't know if it's of any use, but this article has the AM60-550A DIP chart:

http://antiqueradio.org/HomeTVTransmitter.htm

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

That usually means bad power supply filter caps.

Dave

Here is a link to a copy of the switch settings document.
http://www.adi.com/~schulz/misc/switch_settings.pdf
It starts out with some information on an option to work on some unusual frequencies and then goes on to list the normal switch settings.

Note that the last page listing the settings for UHF broadcast is for the translator version, but I found that they also work for the modulator version if you realize the stitches 1 & 2 correspond to switches 2 & 3.

The 550B only has 8 channel switches. When I attempt to set them like the first 8 on the chart for a given channel, for example, channel 3:
The CATV switches are set to UDDD for broadcast, and the channel switches are DUUU DDUU, the power light blinks very fast and it does not broadcast on any channel.

For the 550A, for VHF broadcast 2-13, the first 4 switches should be DUUU, exactly reverse of what you report. Unclear the diff between 550A and 550B, but probably not that much. Perhaps you're reading the chart in inverse. Black bar is switch position, not white space. Correct?

Edit: Rereading your last post, it does look like you do have a block of 4 switches followed by a block of 8. If so, the following does not apply.

The first block of 4 switches on the chart (labeled 1 on the chart) make some very small changes in frequency required for some odd cable channels. I expect that your modulator just eliminated them as unnecessary. Try setting your modulator up using the settings from the block of 8 switches labeled 2 on the chart.

I tried the following settings:
UDDD DDDD DDUD ch 2
UDDD DDDD DDUU ch 3
UDDD DDDD DUDD ch 4
UDDD DDDD DUDU ch 5
UDDD DDDD DUUD ch 6
UDDD DDDD DUUU ch 7
UDDD DDDD UDDD ch 8

It will broadcast on the channels indicated with the above settings, but the power light blinks very fast and the picture and sound are interrupted by a constant popping which seems to be in sync with the power light flashing on the modulator. I may just have a bad unit. If I try to get another one, I'll go for the 550A.
Thanks.

My Blonder Tongue is the B and I have no problems with it. You might just have a bad unit.
Mine is the AM 60-550B w/Opt 4 -- whatever option 4 is.

My BT also has a set of 4 DIPs and right of those is a set of 8 DIPs.
I have them as UDDU DDDDDUUU or 1001 00000111 where U=up, D=down.
I use Channel 7 (0111) and broadcast using an old Rabbit Antenna.

This manual shows UDDU is the setting for the Broadcast band:
http://www.cerant.com/BlonderTongue/MAN ... 0-550B.pdf

Carl

I stand corrected. The "B" is much more intuitive if you know binary. No need for a chart.

Try UDDU for the first set. According to cwmoser's manual & suggestion, that should fix it.

Thanks for the manual Carl. I will revisit this when I have a chance. Does the power light on your 550B blink about twice a second when set to a valid channel ?

I see an AM60-450A on ebay. Does anyone know if that would make a good transmitter for vintage tv's ? I'm not sure what the difference is between a 450 and 550.

In addition to the AM60-550B, I have one of these:
http://www.ebay.com/itm/BLONDER-TONGUE- ... 2a1c19920c

Its a Blonder Tongue BAVM-Z and reasonably priced. Unlike the AM60 series, the BAVM-Z versions are set to a fixed channel. This one is channel 6 only.

The only thing that makes me suspicious is that someone has already attached the RCA adapters on the rear for Video In and Audio In indicating that it might have been used as a transmitter for vintage TVs.

Carl

The 450 part of the model number is the highest frequency that it is specified to put out. The 550 will work up to UHF broadcast channel 27. The 450 stops just below the UHF broadcast channels. That said, I tried my 450 on the UHF channels and it worked. However, I did keep the output power setting fairly low. It is possible that I could of overheated the output amplifier if I ran the frequency up at high power.

Note that cable channel 27 is a much lower frequency than UHF channel 27. In general, all of the cable channels are below the UHF broadcast channels.

The 60 part of the model number specifies the maximum power output.

If it still does not work after resetting the last one of those first 4 switches, you could try replacing the capacitors in the power supply.

When I bought my Blonder Tongue 450, the Ebay picture clearly showed the power cord cut off. Done by the tech, so it can't be put back in service.

I figured for the price, what the heck. No one else bid. I think it was $25 or $26 with shipping. Thought I would be a sniper's victim, but no.

I found some power supply caps were toast, and a resistor was scorched. The strange thing is that the hardware for the 2 of the 3 regulators was missing, so they weren't attached to the chassis, which is the heat sink. What the heck? They were hanging by their leads. If you didn't more the chassis, you may not have even noticed they weren't secured. I did find the nuts rattling around under the ckt. board. Tech started repair, didn't finish? B-T never tightened nuts properly, and rack vibration from cooling fans shook it loose? Guess your best. Cover was on tight, all screws in place, which would not be the case if the tech did start a repair.

Replaced the 2 caps {close value used parts I had in the junk box}, alcohol cleaned the old heat sink goo off, renewed same, new mounting hardware. Works perfectly. Including the scorched resistor. Someday I'll get ambitious, and change it. Someday.

As they say, "Works for me".

John S.

Beaconhunter - Glad to see you got your 450 to work. The first agile modulator I aquired was a BT FAVM 450 and it didn't work. There are two separate sets of DIP switches for the 450: 8 channel setting switches accessed thru the back of the panel and 10 switches accessed thru the top. A chart was provided for setting the 8 channel switches but nothing for the 10. After some research, I located the switch setting chart for the 10 top located switches, and am posting the settings here.

From left (switch # 1) to right (switch # 10):

STD: UUDDDUDDUU (this is the correct setting for our use)

HRC: DUUUUDDDUU

INV: UUDDDDUUUD

After resetting the 10 switches to STD, the 450 worked, kind of. Audio is OK but the video is scrambled. I've got $40 total in this, and have bigger fish to fry than trying to fix it so I tried again.

The next try was a BT AM60-550 for buy it now of $45 + $20 shipping. When the unit arrived, it was NIB ! ! ! Needless to say, this more than made up for the 450, and it works great ! ! !

Turns out mine had a bad main board in it. The power supply checks out good without a load, but when I connect it, the main board draws excessive current causing the regulators to get hot and the voltages drop. I just bid on another B-T AM60-550B. Hopefully between the two, I'll get one working.