[Elecraft] [LP-PAN] Re: K3 Overload from WYFR

[Steve Ellington]

Thanks for the tip. I disconnected the LP-Pan and didn't notice any 
difference in the buckshot level. I really can't judge what the S meter is 
telling me due to QRN etc. but when ATT is engaged, the QRN drops down 
somewhat but the buckshot actually comes through more clearly.
Steve Ellington
N4LQ at carolina.rr.com
----- Original Message ----- 
From: "K8TB" <k8tb at bosscher.org>
To: "Steve Ellington" <n4lq at carolina.rr.com>; "'Elecraft Reflector'" 
<elecraft at mailman.qth.net>
Sent: Sunday, June 14, 2009 9:23 PM
Subject: Re: [Elecraft] [LP-PAN] Re: K3 Overload from WYFR


>    An AM station can easily produce "buckshot"  to 40-50 kcs's out. The 
> reason you don't hear it very often in the US, is that on the standard AM 
> band, the AM stations are very bandwidth limited. The NRSC curve is rather 
> tight, and every AM station has to certify it is within that mask every 14 
> months or so.
>    I'm not sure of this, but I think US shortwave stations are not 
> required to have any NRSC type filtering. Hence, the buckshot can go a 
> long ways.
>
>    Disconnect the LP-PAN, and measure/estimate the signal strength of the 
> buckshot at, say, 7005. Now, turn on the attenuator. If the level of the 
> buckshot drops by the level of the attenuator, then the radio station is 
> producing the buckshot. If the attenuated level drops 2 to 5 times more 
> than the added attenuation, that then shows that the K3 is overloading.
>
>    My Sunday night guess? The station is producing the buckshot. Just an 
> increase of .3 Db drive after the audio limiter can make just about any 
> transmitter produce garbage.
>
>    Tom Bosscher  K8TB  broadcast engineer for 3.5 decades...
>
>
> Steve Ellington wrote:
>> Lyle: Yes I do believe the LP-PAN is being overloaded but still, I do 
>> hear that buckshot modulation from WYFR up to about 7010kHz on the K3 so 
>> it too is being affected although not as much.
>