stretchyman2k@googlemail.com
I’m just about to start a new build of 50 Transmitters and have decided to do 3 variants.
1; 12W, Fixed frequency but changeable by swapping out CPP oscillator, Hammond 1590BBSBK case (small), Direct PWM modulator. 200KHz B/W below 3MHz and 500KHz B/W upto 8MHz. 24V. $200. Audio response 20Hz - 10KHz. Ideal for 12V (3W carrier) and using leaky feeder antenna for broadcasting around the home.
2; 20W, Fixed frequency but changeable by swapping out CPP oscillator, Hammond 1590XBK case, PWM modulator and Modulation tran (custom), 200KHz B/W below 3MHz and 500KHz B/W upto 8MHz. 14V. $250. Audio response 100Hz - 7KHz.
3; 50W, Programmable frequency (programmer supplied), Hammond 1590XBK case, PWM modulator and Modulation tran (custom), integral fan, 200KHz B/W below 3MHz and 500KHz B/W upto 8MHz. 28V. $300. Audio response 300Hz - 7KHz.
ALL designs are single band (200m would be 1.4-1.6MHz or 1.6-1.8MHz, 43m would be 6.5-7.0 MHz, 48m would be 6.0-6.5MHz etc) Class D/E and VERY efficient, so ideal for battery/field operation.
Power level quoted is very conservative CARRIER power and peak power is 4 times this.
The CPP oscillators are dirt cheap (<$5). I’m happy to supply one particular frequency on most bands but if I can’t supply exactly what you need, you will have to purchase it yourself from DigiKey. I’ll supply 6925KHz ONLY for 43m. If this is a problem, please let me know! I can also provide a ‘Selection’ on request. I know there’s folk out there who are ‘Concerned’ that buying an oscillator on an ‘Illegal’ frequency will ring alarm bells and the feds will come a knockin’, please believe me they wont!
ALL transmitters have a rock steady carrier and have now decided to use CREE SiC devices for their ruggedness. The cases are straight from the manufacturer with all work done to ensure consistent quality.
All the Mod trannies are manufactured by a transformer manufacturer and are dipped in varnish.
Postage is ($30) tracked and signed for ANYWHERE in the world, I have never lost a unit in transit!
Paypal direct via friends and family to avoid fees. RFTEKdotLTDatVIRGINMEDIAdotCOM.
If you’re not sure and we haven’t done business before then using regular Paypal will incur an extra 10%. Will eventually put them up on eBay with a 20% surcharge.
ANY questions? Please ask.
Regards
Stretchy.