Hi ...

I've been using a MC1496 as a mixer and decided to try those SBLs from
Minicircuits. But the models that cover down to few KHz are quite expensive
and not available here.

Re-reading the Minicircuits book I have (from 1993, 700 pages or so) they
say that for some applications we can use the SIG port as output and the the
IF port as input when we need to "receive from DC to several MHz".

This is the case below 500KHz for cheap SBL1, SRA1, etc or even to an high
intercept home made DDBM. The isolation remains more or less the same, so
the SWR.

I checked this inverting feature on SBL1, SRA1 and TFM2. All units gave the
same insertion loss (6.5dB) and produced the same LO attenuation at receiver
input (-45dBc). I use a MAV11 as post amp.

The performance actually is better than the MC1496 bug (less noise) and 82Hz
ZEVS signal still there, so the regular utilities on 16K, 18k2, 18k3, 19k8,
21k4, 24k0 ... and some new ones between 50K and 100K yesterday (rtty/msk).

73
Marcus
PY3CRX/PY2PLL
S. B. do Campo - GG66rf
http://py.qsl.br
Active from "DC" to 24GHz