AR88LF, Your thoughts.

[Shaman]

Hello i have a Canadian made AR88LF, communications set, it performs well but i think it could do a lot better, what are your thoughts and ideas on this radio....Alan.

[Skywave]

Hi!
When you say "I think it could do a lot better", in what regard do you think it lacks in performance? Is this the SNR, selectivity, dynamic range, for example? Or are you comparing its overall performance with much newer radios that, say, use modern semi-conductors. If you believe that you have 'performance / not-to-spec.' issue with it, tell me a bit more please: I may be able to advise further.

Al. / Skywave.

[Shaman]

Hi Al, i dont expect stations by the million, and i know a lot of the old stations are gone, on line other frequencies etc, but its had a going through, from mains transformer to valve change (complete) to caps, especially the old bathtub caps, odd resistors here and there, but perhaps it could do with, re-alighnment, i know this is a biggish job on this set scope etc, i just feel there could be more selectivity.....perhaps its me its t tad older than me and i have bits going low performance...regards...Alan.

[Skywave]

I see: thank you for the explanation.

Yes, things are a lot quieter on the short-waves these days compared to 30 - or so years ago. The current dip in propagation conditions doesn't help either.

As for IF realignment, that's not such a big job you know. The most critical feature is discovering the frequency of the crystal filter - and then aligning all the IF cans to that freq. as centre. I've done exactly that on many sets: CR100, various Eddystones, and even a few AR88's. You don't actually need the "scope/wobbulator" approach to obtain an IF response that is satisfactory: it just takes longer this way than by using the "scope/wobbulator" method. Obviously an accurate sig. gen is required - accurate not only in freq. setting and stability, but also accurate in its O/P attenuator. And an O/P indicator that is sensitive to small changes in signal level: I use a Marconi A.F. power meter and a Tek. 'scope. This set-up always work fine for me.
On this same subject of selectivity, apparent lack of, it might just be that you've got used to other receivers which don't have such a cramped dial, in terms of MHz per inch on the tuning scales.

Al. / Skywave.