DEAR JOHN, GOOD MORNING FROM PAKISTAN. VERY INTERESTING YOUR AM TRANSMITTER PROJECT. THIS REMINDS ME OF MY WORK IN 1974, WHERE I CONVERTED A TECH RF SIGNAL GENERATOR MODEL TE- 20, INTO AN AM TRANSMITTER WITH VARIABLE FREQUENCY FROM 500 KHZ TO 1500 KHZ. I ALSO USED IT ON 1000 KHZ FOR TRANSMISSION. IT WAS GOOD FOR 5 KM RADIUS WITH 59 SIGNAL ALTHOUGH SIGNAL COULD BE HEARD FOR A RADIUS OF 10 KM. I ALSO USED A MEDIUM WAVE FERRITE ROD FOR OUTPUT. A 2 WATT SOLID STATE AUDIO AMPLIFIER KIT FOR MODULATION. I PUT A POWER TRANSFORMER OF 220/12 VOLTS IN REVERSE ORDER AT THE OUTPUT OF 2 WATTS AUDIO AMPLIFIER TO MODULATE HT SUPPLY OF 150 VDC USED IN THE SIGNAL GENERATOR TE-20. RF SIGNAL GENERATOR HAVE TWO TUBES 12BH7 AND 6AR5. I REMEMBER I USED 6AR5 AS AN OUTPUT POWER AMPLIFIER, WHICH IS USED AS 400 HZ OSCILLATOR FOR MODULATION IN TE-20. I WISH I COULD STILL HAVE IT BUT UNFORTUNATELY I DISMENTLLED IT AFTER ONE YEAR IN 1975. BY THE WAY, DEAR JOHN, YOUR WORK IS BETTER THAN PROFESSIONAL EQUIPMENT MANUFACTURERS. I SUBSCRIBED YOUR CHANNEL AND HOPE TO SEE MORE INTERESTING STUFF. THANKS AND REGARDS TO YOU AND YOUR FAMILY. KHALID PARVEZ, AP2KD. ZAMAN PARK, LAHORE, PAKISTAN. WHATSAPP +92 345 424 4714. EMAIL: AP2KD@YAHOO.COM
i have a vintage am radio that's battery powered. and i want to get it working but i don't know what voltage it needs. It's a watterson am radio. and i have no means of powering it up. can you tell me what voltages i need to make it work. i replaced 2 capacitors in it that were dead, but the rest are disc capacitors.
I am not familiar with a Watterson radio. Just do a Google search on line. Give the Watterson name and the correct model number. Ask for schematic or circuit diagram. You will probably find something.
find the tubes which look the most similar to it from examining the outside, try to restore the power to each tube filament 1st, be careful not to have too many volts more than it takes to warm up the tube cathode orange-red, if anything gets white hot the tube may have issues or it could randomly be damaged by strong shaking or a higher B+ plate current than the tube could handle, creating a cathode-heater shorting or cathode poisoning, this permanently ruins the transconductance and you may see ionizing gas if the tube begins to leak, the flashed getter will turn more white instead of a mirror if air is leaking inside.
Wry nice John. I really like your cover you made. Looks great! I’m working on a CW transmitter using an A6ag7 oscillator and 6v6 output. I’m debating on adding an additional 6v6 or adding a final with dual 6146’s. Either way, I’ll need a cover and was heading in the same direction you did. Awesome work! Dave
3:00 it's wild when ya speak in First and Third person at the same time John, but it is very Harmonic and possibly even Polyphonic. You're a pretty slick Dude, I got my eye on you 🧐 😃
