[davidgem1406]

Hello all, I hope you all had a good Christmas and New Year.

Having been away as from December 10 until January 13 it is now time to pick this up again and post the results of our pre, and early, December endeavors, and see what we can do from here.

We used the information posted by John on #9 at 16 Nov 18, the table below shows this.

Or it would if I could paste it here, but I will attach it as an Excell document 001, and a second table 002.

The problem we had was that we could never reach a point where no further change was found.
Having repeated the adjustments time after time a change at one end always resulted in a shift at the other end. A point could never be found where no further change was required.
The result was that the scale never tracked with any accuracy.

We tried higher and lower frequencies for the start points but always ended with the same problem.

Eventually, we decided to set the start points using radio stations at the upper and lower ends of the scale and then check the tracking across the scale using the known stations.

My friend then took the set back to London and checked it out there. The following are the results he sent to me on the 3rd of December. These results are how the set is at the present time. (Table 002)

Hi Dave,
I’m back in London and have set the radio up with the aerial.

Stations receivable, their broadcast frequencies, and the corresponding display frequencies are as the attached Excel file (Shown below).

Lowest receivable is Radio 2 on 89.1 and highest is Classic FM on 101.1, so there is a band-spread of at least 12MHz (close to the design spread of 12.5MHz).

But in terms of the display, that is compressed into a display range from 91.2 to 100.0 or about 9MHz.

So we are pretty much where we go to on Friday.

I’m guessing that the reason we got so bogged down today was perhaps that, as you spotted towards the end of the day, the capacitor has two positions that work at the top end and we unwittingly wedded ourselves to the wrong one.
(My Note: the capacitors are the flat round type that can full rotate in a circle, and will have 2 positions dependant on the direction of rotation that will determine the position used.)

The lower half of the scale is still well out, but the upper half is much closer to the relevant scale markings.

The question is now what do we do to look at correcting this problem and getting things to track correctly.

All suggestions and ideas are very welcome.

Best regards
Dave