As shown on the circuit diagram (Fig.1) bridge the HT contacts with the bleeder resistor 3.3 M ohms on
the back of the switch. ( this is there to keep the 8/10 uf cap charged and thus giving an instant voltage
onto the product detector on selection to stop frequency blip.)
Having completed the audio filter network I mounted mine adjacent to the coil pack and supported it us-
ing a bit of 12 gauge wire clamped under the coil box lid. Connect the new anode feed from the ssb can
through a 0.047 uf cap (in my case all I had) to the filter and the output across the 47k to the free bottom
terminal on the ex BFO switch for the audio feed. See Fig.17 below.
Don't forget to plug a new EK90/6BE6 valve in.
So its a final check over of all the changes and switch on.
With all these changes the oscillator section of the product
detector will have shifted in frequency so we need to set its
frequency.
Now the IF centre freq is about 450 kHz +/- 1.5 kHz so we
need to obtain a stable frequency to give a steady signal.
No matter what you use, tune the receiver to it on MAX selectivity for a maximum reading on the S me-
ter. (CRYSTAL to OFF) Select the product detector and set the BFO variable capacitor plates by eye to half
way. Set the white dot on the knob to centre on the eschaton if needed by undoing the grub screw and
rotate to suit.
Adjust the coil in the product detector can for zero beat.
That's it job Done.
Hope all goes well Cheers
Roy Kavanagh
GM4VKI
Fig.17.
