[BC] AM Loads

[Moore, Randy]

Because the load is broadbanded and the atu is narrow.  Look at your output, you probably have spurs or harmonics.


Randy Moore



----- Original Message -----
From: broadcast-bounces at radiolists.net <broadcast-bounces at radiolists.net>
To: Broadcasters' Mailing List <broadcast at radiolists.net>
Sent: Wed Mar 25 15:09:59 2009
Subject: Re: [BC] AM Loads

Ya know, it's strange, I have a Bird 82C 2.5KW dummy load which I 
think is 50 J0 and AM-1a's load into it fine with no reflected to 
speak of.

I've never actually read the input of the 82C to see if it's really 0J 
but it does read 50 ohms.

I'm trying to reconcile why the BE likes the dummy load but doesn't 
like an ATU input of 50 J0.

Has anyone checked the reflected power at the BE output with a bird 
43?  If so how did that work out?

I'm looking for the right slug for my 43 but ones for the BC band are 
hard to find.

Ron D

----- Original Message ----- 
From: "Kevin C. Kidd CSRE/AMD" <kkbroadcastengineering at gmail.com>

> The correct answer is [a].
>
> BE AM1 transmitters do not like 50j0.  Fold back usually won't allow 
> the
> TX to make full power into what should be a "perfect" load.
>
> I don't recall exactly but they show lowest reflected on the TX 
> metering
> at something like 47-j7.
>
> Later,
>
> Alan Alsobrook wrote:
>> Ronald J. Dot'o Sr. wrote:
>>
>> A. Transmitter output is not 50j0. Some of the boxes seem to like a
>> slightly capacitive load. Component failure can cause output 
>> network
>> mismatch. (have an Omni that only likes 41 -j14 due to bad chip 
>> caps)
>>
>
> -- 
> Kevin C. Kidd, CSRE/AMD



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