Topband: Collins 75A4 vs 51J4

[sire@iinet.net.au (Steve Ireland)]

G'day

I have been very intrigued by some of the recent postings with regard to
using the Collins 75A4 on the topband.

Here in Western Australia, 75A4s are unobtainable, but there are a few
Collins 51J4 around (hidden away in very dark corners). Does the 51J4 offer
a similar single conversion/250kHz mechanical filtering/1.8MHz performance
to its ham band brother the 75A4?  If so, I might go on a scavenger hunt!

Vy 73

Steve, VK6VZ