Does anyone know of any transmitters that are bit more powerful than the Blonder Tongues modulators and ones that are equivalent.. Something that would transmit several blocks away.. I did a search on transmitters and all I came of is these that are high powered and lots of $$$ too..

http://www.alibaba.com/product-detail/FMUSER-FM-15T-15W-TV-portable_1714496948/showimage.html
http://www.aliexpress.com/store/product/FMUSER-FM-100T-100W-Analog-TV-transmitter-UHF-VHF-PAL-NTSC/904382_2027365534.html
http://www.aliexpress.com/item/FU-518A-300W-Low-price-300W-VHF-TV-Transmitter-Analog-TV-transmitter/2035977525.html
http://www.fmuser.net/content/?642.html

FM/TV microwave transmitter, what ever that means..
http://digitaliontechnologies.com/shop/product_info.php/products_id/570

Here's one on eBay.. Think the FCC would be knocking on your door using this thing?
http://www.ebay.com/itm/Axcera-800-Series-UHF-TV-Transmitter-500-Watt-Low-Band-Power-Amp-/181574311432?pt=LH_DefaultDomain_0&hash=item2a46ac1e08

I think you are limited to something like 7W for legal low power TV transmission....
That said if you got a wide enough bandwidth amplifier, and fed it the combined signal of several modulators attenuated down to a level which would yield the legal limit or less power per channel from one of those 30W units it could be used legally...

Here is a cheaper idea: 6 Meter ham radio transmitter booster tube amps operate close to the bottom of low band VHF TV band. If you could get such a unit cheaply, and modify it for the TV band (take the RF filters that are tuned to the 6 M band and re-tune them for VHF), then it could possibly work as booster for TV.

I've read some 6M HAM stuff on the design of those amps in hopes of building one to turn an old VCR into a cheap ass channel 4 transmitter.... So far I'm not able to make it work off a VCR, the tiny signal can't drive the tube, but it will amplify one of my BT modulators (which could allow me to do some pirate analog TV*).

* There is a part of me that would like to pirate transmit some stuff county wide a day or two a year....

Those microwave units don't work on any frequency normal TVs can tune, and thus would need a redesign to be useful for your purposes.