[Test-Equipment] FS: Heath IM4180 FM deviation meter

[Robert Roehrig (K9EUI)]

----- "Sheldon Daitch" <sdaitch at mor.ibb.gov> wrote:

> I suspect the scanner is also a narrowband receiver as well.
> 
> Howard wrote:
> 
> >Nope it was the radio cuz I listened on the scanner first before
> setting it.

You cannot measure peak deviation by ear with a nearby scanner/receiver. The signal is so strong that you will be detecting a signal that can be way down the slope of the selectivity curve. The best way to do that is to insure that the RF signal is low enough that it's just a tad above full quieting. Even then it's not a very good way to do it. lacking a good calibrated monitor, the best thing is a scope on the discriminator as has been mentioned. 

Even with a 5 kHz system, it is best to set the transmitter peaks to 4.5 so when the rig is in the fringe area where it may not be full quieting, it will still not be overdeviated in the receiver.



-- 
Bob Roehrig
630-844-4898
A.U. Telecom dept.
K9EUI  WD2XSH/19  W9ZGP