W7RY Heathkit SB-220 QSK Board
This sale is for a HIGH QUALITY PC board only as shown. The picture of the populated board is for example only. The board is 2\" X 2.2\" and mounts with a 6-32 screw or standoff.Schematic and parts list sent via email after sale. No other documentation included. The schematic contains all the information you should need to install this board into your Heathkit SB-220 linear amplifier. The board has adjustable bias so you can set the ZSAC (idling current) to your desired level. The board also provides \"soft key\" as part of it\'s design. Your transceiver will only see 10 volts DC @ 1ma to key the amplifier. You can also key the amplifier with + voltage. (5-20 VDC @ < 10 uA)The parts to populate the board are $12.30 from Mouser Electronics. (Parts list included)You will need to purchase a 12 volt input relay, (available from me in a separate sale) and a 26.5 volt vacuum relay such as a Jennings RJ1, Kilovac HC-1 or a VHC-1 from Max Gain Systems. I highly recommend Max Gain Systems for your vacuum relay purchase.One side note..
I have observed that in ALL of the amplifiers (SB-220, SB-200, TL-922, AL-82, Drake L4B) that I have installed FAST W7RY QSK RELAY systems into, have QUIT arcing in the the tuning capacitors even with no additional parasitic suppression methods! In my opinion, the reason for 99.5% of tuning capacitor arcing is improper T/R relay sequencing and SLOW open frame relays that cant keep up with your modern transceiver.
This is not a kit. It is a bare circuit board, schematic and limited instructions. If you are not familiar with amplifier construction, design and how they work, you may have difficulty with this board. Please get an \"elmer\" to help you.Because I no longer get your email address fromwhen I get notified of yourpurchase,you must email me at the address shown in thepictures,so I can send your documentation. Please include your ID in your email.International shipping please note! I ship by US mail. I cannot track an item any better than you can. It takes time for items to get to you. I cant control this time, nor can you. I\'m sorry, but I cant be responsible for the mail system world wide. Please understand this. Thanks!Thanks and 73Jim W7RY
