AM Broadcast Transmitter with HD Pre-amp, Zenith, Scott, RCA Fada or Crosley
C rules Part 15 this is a perfectly legal transmitter And you need no license to use it. The rules state that the transmitter may only transmit 100mw input into a 5 meter antenna and transmit no farther than 200 feet and this transmitter meets all these rules.
The transmitter electronically is overbuilt on purpose so that it will last a lifetime. No part in this transmitter is overworked in any way. And another big plus is if you get a power surge or spike this transmitter has a better chance of surviving than the transistor models out there. Transmit tuning uses a ferrite core system that eliminates drift, once you set this transmitter to the frequency you want it will stay there like a rock.Specifications Power 115-120 volts AC Power usage 9 watts Size. 6SA7 Frequency 550khz to 1650KHZ. Default setting is 1000KHZ Can go as far up as 1800khz for Europe on request.
Its easily tuned with an Allen wrench or hexagon radio slug tuning tool. (Will gladly set it to transmit on any frequency you want) PLEASE tell me what frequency you want to use? Power in 1 volt peak audio power (headphone volume) Power input to oscillator tube 100mw RF power Audio. Antenna 15 foot of #20 wire Frequency drift +- 2 cycles after warm up. 5 meter 18' antenna wire.
Attach the antenna and feed the wire out later after testing you can put up more wire to cover the whole house. Plug in your RCA to mini patch cord into the transmitter and into your source of audio (headphone level) Use a headphone and make sure you actually have audio coming out of the source. Set the transmitter volume control to just barely on for headphone volume audio devices. Plug unit into a 120 volt ac outlet. Turn on one of your radios and set frequency to 100 or 1000khz (or the frequency you had me set it to).
Tune your radio to that frequency and you should hear your programming near the spot you tuned the transmitter to. Now that you have it up and working you may want to add more wire so that all your radios will receive the signal well. Keep the Volume control on the transmitter very low, I pre-set it to 9:00 and seems to work well at that setting. If you need to change the transmitter frequency use a 2.5mm Allen. Wrench or best would be a plastic tuning tool 2.5mm, turn clockwise to go down frequency and counterclockwise to go up.
The Volume control and volume of your source audio will have to be adjusted a little to get everything sounding good, make sure your receiving radio is loud enough then adjust your audio source so the distortion disappears. What happens is if the drive either from the source or volume control on the transmitter is too high it will over modulate and make the waveform not what it should be and comes out as distortion in the receiving radio, so lean towards keeping it low.Till you have it sounding good then crank it up slowly. Know the Allen wrench tuning sounds like a lot of bother but its worth it because. A permeability tuned oscillator (PTO) is more stable than a variable capacitor in that it will drift very little.
The famous Collins radios all used a PTO tuned oscillator and also the Drake. Suppose the reason other radio companies back then did not copy Collins is they had a patent on the PTO. Other people make claims that their transmitter does not drift, but when a coil and variable capacitor are warmed up slowly by the heat of a tube the capacitor plates become thicker because metal expands when it is heated, and the coil becomes larger when the copper wire expands, what the result is the transmitter goes down frequency. To compensate for what little drift mine has on the coil is a small.
Negative compensating capacitor that looses capacitance as its warmed up, and like magic the transmitter drifts very little. The item "AM Broadcast Transmitter with HD Pre-amp, Zenith, Scott, RCA Fada or Crosley" is in sale since Monday, October 02, 2017. This item is in the category "Collectibles\Radio, Phonograph, TV, Phone\Radios\Tube Radios\1930-49".
The seller is "richsonic" and is located in Las Vegas, Nevada. This item can be shipped worldwide.