Check the listing for details. 80/40/30 METER CW QRP BATTERY POWERED HAM RADIO TRANSMITTER (W/CRYSTALS). Condition: Used. Listed at 135.00 USD. This item has exposed high voltage underneath the chassis. I used good wiring practices, but if you are not experienced in working around lethal voltage, then PLEASE DO NOT purchase this item. The circuit has a battery powered dc to ac inverter, and the no load dc voltage underneath the hood is about 250 volts rectified dc (about 185 volts key down). So even though the power source comes from harmless 9 volt batteries it can still be lethal if not handled responsibly. Okay, all the drama aside, this is a self-contained vacuum tube ham radio QRP 6G6G cw transmitter. With fresh batteries I get about 2.2 watts output on 80 meter cw. The dc power converter, using the 3 nine volt Li-on rechargeable batteries (not included) will run for about 2 hours before needing to be recharged. I've been using 600 maH batteries, but have noticed online that the 9 volt rechargeable Lithium batteries are now available in 1000 maH versions. So with 3 of those installed you'd likely get close to 3 hours of operation before needing a recharge. The dc inverter circuit employs a pair of 2N3055 power transistors, working with a common 6.3 volt (117v primary) transformer. The output is then rectified by a 1N4007 diode, then filtered. I'll also include a little 9 volt battery connector (last photo) so that you'll be able to power the radio from an outside source if desired (abt 1.5 amp capability). But under no circumstances should you apply any more than 8 to 9 volts dc. I've even used a common 9 volt wal-wart transformer to power this transmitter, but those things typically employ some sort of a switching/sawtooth circuit which produces a noticeable rasp on the cw tone. The inverter uses a little 6.3 volt filament transformer with a turns ratio of about 18.5 to 1. This means that increasing the voltage by one or two volts could potentially blow the power supply. So keep it to 9 volts max and you'll fine. The 9 volt Lithium-ion batteries typically provide about 8.2 to 8.4 volts, fully charged. This little rig loads up nicely on 80, 40 and 30 meters, with the plug-in inductors and 3x QRP crystals provided (one for each band). In my experience I have very little issues with chirp when using the 49/U QRP crystals. I sometimes get a hint of chirp on 30 meters but can usually tune it out by careful adjustment of the plate input capacitor to the Pi-network tank circuit. I'll be listing a 160 meter version (i.e. 160/80/40 & 30M capability). It looks the same, but has an extra switch which adds a 250 pf shunt to the Pi-network antenna load capacitor. That, plus the 160m inductor plug-in is all you need to also work 160 meters. I will include a hand-sketched wiring diagram of this item, plus a sketch of all control panel functions. SHIPPING TO THE UNITED STATES ONLY