Gain Master Mystery

[Mark Malcomb]

Sorry for my stupidity, I have a new gain master that is still temporarily set up In an umbrella hole on my deck. perfect size. I've been using it to test a few radios. It has a great SWR of 1.2 max. I get next to no rx hits on all three radios. I decided to check impedance at my meter between radio and antenna. DEAD short. Went to antenna took off coax checked between center pin and shell. DEAD short. This don't seem right. My SWR is great. Looking at the GM I don't know what could be shorted. The mast is isolated from the shell. Payed a bit for this GM, didn't know if I totally missed something. If this a dumb question I truly apologize in advance.
Thanks All.............MM

 

[sp5it]

It should be dead short for DC. No matter for RF.
Mike

 

[Mark Malcomb]

Thanks Mike. Glad I spokeup
MM

 

[RT431]

Not surprising that the GM will show a dead short. The A99 and Imax will also show a dead short.

 

[tba02]

The GM really prefers to be in the clear. You may not be high enough or have too many things in close proximity.

 

[M0GVZ]

Lack of height is likely the reason. And as others have said something which appears as a dead short to a DC meter isn't necessarily going to be for RF. If you look at various diagrams for things like Baluns you'll see that the centre and shield of the socket are linked to the same wire on the other side of the toroid.