A very capable engineering colleage of mine mentioned some time ago that
an AEA he had purchased worked very well except for one thing -- the
reference point appeared to be inside the instrument. He said it was as
though there were another length of line (about 5 cm as I recall)
inside. For example, measurement of a short circuit would indicate the
amount of positive reactance you'd expect from such a line. This might
not be too important for general purpose HF use, but would be a problem
with some measurements, especially at high frequencies. It could be
removed by mathematical adjustment of the measurement results, of course.

I mentioned this problem to the AEA folks at Dayton, not long after it
changed hands, and they might have fixed it. Do you see this phenomenon?

I saw a similar thing when I spent a few minutes playing with the very
first model of Autek. I don't see this with my MFJ.

Again, the problem might have been fixed, but it's something to look
for, particularly on an older used unit.

Roy Lewallen, W7EL

J. McLaughlin wrote:
I use a GR 1606A when its capabilities are needed. I even salvaged
another from being scraped so I have a back-up.
However, for most tasks, I find that the AEA VIA is the cat's meow.
For instance, when trying to tune a Matchbox to strange frequencies, the
VIA tells one which way things are going.
I have not tried to use the VIA in the presence of strong broadcast
transmitters. At work, we have HP (Agelent) network analyzers and
standards to use as comparisons.
AEA also makes, and I use, a modest TDR that is good enough to be
used to keep track of transmission lines, connectors, and in-line
protection devices.

As Roy, and others, have said: when you need a GR, you need a GR.
Before I bought a 1606, I was once loaned the 900 something predecessor
to the 1606. This instrument is inside of a small, copper lined
suitcase and the particular instrument had been used by the military
since about WW2. The outside showed use. It was spot on with my
standards and, when I opened up the case, the insides were still bright
and shinny. GR made quality instruments.
Though I have not used it, somewhere I have a Delta bridge that was
given to me.

Go for the VIA for HF. You will not be disappointed.

73, Mac N8TT