Help Understanding RF Transmitting

[Electronic M]

Amplifying your archer video distribution system is not a practical thing. There aren't really amps out there designed for that sort of thing especially at UHF.

You need 40-60 dBmV to get good results especially if your antenna isn't optimized for the channel.

The Blonder Tongue Modulators take line level audio and composite video (the white and yellow RCA jacks on the back of your VCR)... Blonder Tongue uses F-type connectors for RF output, line level audio and composite video...they use RF style connectors for non-RF signals because they were designed for cable television head ends where only screw connectors are acceptable (RCA connectors can be yanked out which would cause many nightmares for their technicians). They make little F-type male to RCA female adapters that are like 1$ each that convert the Audio and video jacks on a Blonder Tongue to the RCA connectors we need.
Just about every VCR and Laserdisc player ever made has RCA composite video and line level output as do most video sources...2 exceptions I can think of are early RCA CED video disc players and some Atari era video game consoles that only have RF output...my basement transmitter has such a CED player and several such game consoles...I tune them on the VCR and feed the composite output of the VCR into the Blonder Tongue to transmit those

There are 4 different Blonder Tongue models I'm familiar with that will do the job of transmitting. There are AM-60 model 60dBmV that can cover a block with the output level set to max, the AM40 40dBmV which can cover 2 houses at full output, the BAVMz family that is halfway between the output of the other 2, and there's some mini modulators, which I have never used, that a bunch will fit in a 2RU power supply/mounting system. The AM series are agile modulators meaning you can change which channel they output. The BAVM series definitely and possibly the mini modulators too are fixed channel so if you buy a unit for channel 2 it'll only ever transmit on channel 2. The agile modulators have the final 3 digits of the model number as the max frequency they can transmit (an AM60-400 can only do VHF, a -550 can do VHF and low UHF, a -860 can do VHF and all UHF). Something to keep in mind with the fixed channel modulators is channels above 14 are cable channel numbers which operate on entirely different frequencies than UHF channels with the same channel number... Some cable channel frequencies overlap with some UHF channel frequencies, but you have to use frequency to translate (IIRC cable 66 is around 16 UHF)... some cable channels are in the FM radio band, some are below VHF some are between TV bands some are above UHF and it jumps around and there's 2 different cable TV frequency schemes IRC and HRC so it can be a PITA to do UHF...

Some Blonder Tongues need recapping at their current age and setting up a good antenna is a process I've written about so many times on videokarma that I rather you search my old posts.