"Jim Hackett" wrote in message
. com...

[snip]

What I was REALLY
wanting to know was if a preselector would help with blocking spurious
signals and images out of my older tube single conversion radios.

[snip]

I haven't used preselectors much, but I do have several 455 kc IF radios.
The simplest S-38 types used a single tuned RF circuit at the antenna. As
expected, these radios don't have much image rejection on SW. The S-40
types have much improved RF image rejection with a tuned antenna circuit and
a tuned RF circuit. The SX-62 has two tuned RF circuits and a tuned antenna
circuit, and is almost completely free of noticable images, although there
are still some bad combinations of weak signals and strong signals 910 kc
above. Going from one tuned RF/antenna circuit to two tuned circuits makes
a big improvement. Going to a third tuned circuit certainly makes a
noticable improvement, but the improvement is not as big as the second.

So, I'd say the preselector should help, but it might not entirely supress
the images depending how poorly your radio currently supresses images and on
the signal strengths of the two signals.

Frank Dresser