Full 900 on a maxtrac

w2rac · Post by **w2rac** » Tue Feb 27, 2007 5:14 pm

http://www.ogdenlabs.com/maxtrac/

I ordered mine and will post back the results.

Richard W2RAC

w2rac · Post by **w2rac** » Tue Mar 13, 2007 8:39 pm

With the mods in place it works GREAT.
Just take your time putting in the SMD parts!

Richard W2RAC

Max-trac · Post by **Max-trac** » Tue Apr 03, 2007 2:20 pm

OK, I have done 2 of these now and CANNOT get the full band.
(varactor diode change, conductive ink)
I DO see lower voltages on the higher freqs now, but no matter how much ink I add, the bottom end won't go any lower.
( I see a slight improvement with a little ink, then there are diminishing results)

I am getting getting about 915 to 928 on the right side with a voltage of about 1.5 to 3V. (tx)
And on the left side, rx from about 918 to 928 with a swing about 1.5 to 2.5V (And tx from 901 to 903 at about 3.5V, NO rx).

KF6HHS had a kit that also had a resistor change, does anyone know which one and what value??
Was it to increase the voltage??

Has anyone made a schematic of the VCO ?

W6JK · Post by **W6JK** » Sat Apr 07, 2007 7:31 am

Hugh is AE6YC now.

His mod includes changing the charge pump resistor, R121, from 5.6K to 7.5K. He uses different varactor diodes in the Tx and Rx sections, but he doesn't tell you what they are. He claims a VCO range of 55 MHz on Rx and 33 MHz on Tx.

Jeff