| Restocking Fee | No |
|---|---|
| Return shipping will be paid by | Buyer |
| All returns accepted | Returns Accepted |
| Item must be returned within | 14 Days |
| Refund will be given as | Money Back |
| Brand | Unbranded |
Check the listing for details. PARTS AND SCHEMATIC 80/40/30 METER CW QRP BATTERY POWERED HAM RADIO TRANSMITTER. Condition: Used. Listed at 75.00 USD. This listing is for the parts and schematic ONLY to build this transmitter. No manual or step by step instructions are included, and no chassis is provided. The circuit can be Breadboarded or made with most any metal chassis. I simply used a mini-sized baking pan to build the one in the photos. Construction is fairly straightforward, but this is a project for those having previous hands on experience in working with the construction of electronic circuits. Once in operation this circuit has exposed high voltage! If you are not experienced in working around lethal voltage, then I do not recommend that you purchase this item. The circuit has a battery powered dc to ac inverter, and the no load dc voltage 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. 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. Again, no batteries are included. All other parts and hardware you will receive with this purchase, including the 6G6 tube, all sockets, crystals, crystal holders, etc. For the antenna connector I have used a BNC, but also have the SO-239's or I can supply a pair of color coded binding post type connectors if you like, in lieu of BNC or SO-239. Just let me know. The dc inverter circuit employs a pair of TIP41C power transistors, working with a common 6.3 volt (117v primary) transformer. The output is then rectified by a 1N4007 diode, then filtered. In the photos you will see 2N3055 transistors, but they are bulky, and after making several of these inverters for different transmitters, I've switched to using the smaller TIP41C 6 amp transistors. 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 to 2.0 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 be fine. The 9 volt Lithium-ion batteries typically provide about 8.2 t0 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. No 49/U type crystals are available for 30 meters, so I will supply the smaller 49/s crystal for that band, which can be a bit more prone to chirp because of the lower power capability, as compared to the 49/U. SHIPPING TO THE UNITED STATES ONLY