Over the years, I’ve managed to accumulate a few more cards than I need for repair inventory purposes. Specifically, I have several Equalizer cards for sale. They are fully restored, tested, and guaranteed. While I have some other cards as well (to be offered at a later date), they are not yet refurbished.
Trying to be fair, I’ve set a price of $30 each plus shipping, which is about what I charge to refurbish one. If you need one, please send me an email at admin at dap310.com. First come, first served.
I am looking for a circuit with modifications to the equalizer card. I found one made by Dana Puopolo but the part numbers don’t match up and I haven’ had any luck finding him. His modification looks to be better for AM.
Here is the article with Dana’s recommended value changes. While I don’t agree with him, do what works for you. Remember, these filters are only 6dB per octave.
https://steampoweredradio.com/pdf/dorrough/Modifying%20a%20DAP%20310%20for%20Optimum%20AM%20Modulation.pdf
As far as the values are concerned, the stock value for C3 was 0.1 uF. I don’t know where he got .03 uF.
I’ll email you his email address. You can ask him.
You don’t think that the factory curves are not beyond AMs frequency response? What would you recommend?
Phil
No, I don’t. The filters are very broad. When I rebuild them, I return them to stock. Mike and Kay Dorrough got it right the first time.