Reference Signal Too Low.

[daves]

Good morning folks.
I have enjoyed the AIM for about a year now using it as both as tool and a learning/teaching aid at the local club.This is the first problem I have found but it may well be "user related"!!
I have been testing an unknown feeder, getting credible results,
when I decided to test a known sample of feeder as a control.
When I tried "Distance to Fault" a few seconds elapsed and then the message"Reference signal is too low" appeared in the top left hand of the display and the program hung up. The only way out was to shut the program down. The known sample was a 6ft length of 300 ohm window line, open circuit at the far end.
Various other feeders (50 and 100 ohm) were tried and distance to fault was fine. Another lenght of 450 ohm feeder brought up the same message.
It was possible to run an SWR and return loss scan on the 450 ohm feeder (2-150MHz) and get a sensible result.
I am using Aim 626 as the control program.
Am I doing something wrong? Has anyone else come across this?
73 de Dave...G4DAX

[Bob]

Hi Dave,

The "distance to fault" function has been extensively revised this year. I recommend downloading the latest version. It has a lot of new features that are handy too.
www.w5big.com/prog_update.htm

When you scan the 2 meter line, does the scan look reasonable? Theta should pass through zero in the range of 30 to 40 MHz.

Hopefully the new "distance to fault" function will take care of this problem. If not, let me know and I'll attack it again :-)

--73/Bob

[daves]

Hallo Bob,
Spot on...worked first time after loading the latest version
(670).
Was it something I'd done or a glitch in the program?
The scan using 626 looked OK and seemed what I would have expected.
Anyway, all fine now and I can get on playing.
Many thanks and early Christmas wishes.
73 de Dave...G4DAX