It improved weak station reception as well so I Left it in. One aside, I found the radio needed a stronger AVC signal to prevent overload with strong stations, so after assembly I substituted a 15K resistor for the stock 27K (these values are what I remember, not having seen the radio in atleast 15-20 years). I went to their website and I'm shocked to see they even still sell the adjustable power supply, and binary clock I built before I graduated in '84! Thanks for posting it Mitch!
Graymark radio kit manual#
I still have the radio, so I think I may have the manual too. Ive now found where the original builder installed a 47Kohm resistor where there should have been a 4.7Ko. When the radio was found to be working, you'd remove the parts and assemble them to the circuit board and complete the radio in its case. Here is part two of the Graymark short wave radio. They were needed to attach them on the breadboard assembly. Ron-C.R.'Ron'Lawrence KC4YOY Antique Radio Collector & Historian kc4yoy(at)carolina.rr. Sure would like to find a nice clean one. Ive been watching ebay for one for some time. The little squares of circuit board sticking out of the board to go into the radio were to be used for the IF's. A Graymark 515 was the first electronic kit I built when I was taking Electronics in high school in 1970. In the ebay photo, the schematic in the box was to be glued over either balsa wood, or craft foam and the included spikes in the bag to the left were inserted in key locations to do a sort of bread board assembly of each subsystem until the radio was complete and working. The manual was full of theory of AM radio, conversion, amplification, oscillators, etc. I may still have a copy of the manual, I need to check at my partent's house ( built one in the early 80's when I took electronics in high school).