The AM Forum

Howdy, Troops!

I came into a hunk of gear that should be VERY useful for amateur use; a Bird 4386
RF Analyzer. Besides forward and reflected RF power, it'll do a ton of other things
besides, like reading the modulation percentage of AM signals. A neat little 3 rack
unit high package with digital readout.  :)

I got hold of the meter and the required "two holer" transmission line section that
holds the slugs. Therein lies the problem...

I've downloaded the manual from the Bird website, but I need a SCHEMATIC for the
beast; that's something that isn't in the book, or available from Bird (proprietary info,
ya know).

The older Bird stuff is set up and calibrated for two different types of slugs. The ones
we're most familiar with (for Model 43 wattmeters) is designed to drive a 30 uA meter
movements.

The higher power (broadcast, etc.) stuff is designed to drive a 100 uA meter
movement. Unfortunately, the 4386 is apparently designed for the 100 uA slugs.

There is a version of the analyzer that is compatable with the 30 uA slugs. I get the
impression that the only difference is a resistive divider network on the slug inputs
to the meter.

Has anybody out there got schematics for the analyzers?

The only alternative to major surgery on it I can come up with is a pair of Op Amps
used to level convert the 30 uA slugs to 100 uA voltage levels.


73's,

Tom "Mr. T." Adams, W9LBB



 

Hi Tom,

I have NO specific knowledge of this device,  but have seen them in catalogs.

You might try calling RF Parts and try to speak with Merit.  He is their tecnical guru (he may be a principal in the biz).   They might have only an interest in selling U something,  but it is wort\h a try.

Thier catalog sez that the 800 line is for ORDERS,  NO TECHNICAL.  (800-737-2787)
The Tech # is: 760-744-0750.  (PST Time Zone)

Sounds like a nice find.  GL   Vic  K6IC