RF Unit modifications and TS-530 Transverter connection

Next step is to install the new coils at L101, L102 and L103, along with the previously mentioned capacitor at C103. (I just got a bunch of 2pF, 500V silver mica caps and am going to try one with a 4-turn L103 next time I have an RF Unit out of one of the radios.)

There are a few more things to do to the board before reassembly can take place. One corrects an AGC overshoot condition and is detailed on AG6K's Circuit Improvements page. It's applicable to both 530 and 830 series rigs.

R12 (highlighted; near J4 and J5 at the lower left side of the board) is changed from 1 megohm to 10-51k, 1/4w. I used a 39k:

R12-Mod.jpg

Next, the components for the TS-530 Transverter Output signal are added. The Taiko Denki TL25-series header was salvaged from a junked TS-930 Signal Board, as were many other parts used in this project series. Skip this step if working with a TS-830 RF Unit, as the components are already installed:

XVTR-RF-Board.jpg

C38 (circled) is a 10pF, 100v NP0 ceramic disc capacitor and R8 (also circled) is an 82 ohm, 1/4w unit.

The last modification - assuming one wants the rig to transmit on the new band, and thus be useful in transverter service - is to locate R45, a 2.2K, 1/4w resistor which runs from J1, Pin 1 to Gnd. Clip or remove it. Better still, remove the resistor and install a 2-pin keyed header. This will be used to take "Aux Band" +9v to band-control logic which we'll build later.

R45 - if present - serves to limit output by means of the ALC circuit...but that's only one piece of the puzzle.