Hi Sandy, Hello to all,
The secret of the Blonder-Tongue AM60-450A popularity is it's phenomenal Max RF output power (for a modulator).
It outputs +60dB/mV which equates to 1.024V on a 50 Ohm load and nearly 21mW out the antenna - enough for 'round the appartment "Broadcasting" with a dipole providing the conditions are not too stringent.
Most other Blonder-Tongue RF Modulators output a lower and more "reasonable" +40dB/mV which equates to 0.032mW of RF power, not enough "oomph" to Broadcast anywhere.
The lazy man's solution is to trot over to e-Bay's RF Amp section and select a model to play the role of RF Final Amplifier. There are nice models by Mini-Circuits & Avantek (now defunct) with Class A linear amplification from 1-10MHz to 200, 300MHz or 1 GHz with output powers ranging from 50mW, 100mW up to half a watt or more. Purchased second hand for low prices, these are really fun modules to experiment with. Caution! anything above a few milliwatts output power must absolutely have an antenna connected before power is applied or the output stage will fry in milliseconds.
http://business.listings.ebay.com/Pa...istingItemList
Personally i operate 2x 100mW TXs in VHF 625/PAL and 525/NTSC with no problems whatsoever (may i say 10 years now). Also allows you to operate mini/micro TVs off their internal whips without dragging a cumbersome ATSC box + yet another power supply cord.
Additional advantages derived from using second hand Broadcast gear is that the output signal conforms to the Vestigial Sideband RF Broadcast standard whereas all consumer modulators output both sidebands with equal intensity.
In practical terms, this means that you could operate several modulators staggered to different channels leaving only one free channel in betweeen, such as 2-4-6,... - with a consumer modulator, at least 2 channels interval is necessary to avoid interference.
Of course, never use a channel broadcasting a legitimate TV content or anything else. Over here in Europe, VHF Band I is totally abandoned and Band IIII is on the way out except for DAB digital radio in some countries (UK, 220MHz band). TV on UHF rules supreme...
See the Blonder-Tongue spec sheets for the AM-60 Series attached to this thread - (can't post twice the same document)
http://videokarma.org/showthread.php?t=234563&page=2
Best Regards
jhalphen
Paris/France