Topband: DX Engineering Preselector

[John Harden]

Carl,

I bought the DX Engineering device because it has the best third order 
intercept. Just see W8JI's web site. Tom has a chart that compares TOI's 
for various devices. I trust his meaurements because they are based on 
facts and knowledge of the RF arena. They are not opinions and 
assertions as one hears often on the reflector...

When comparing receivers it tells us how well devices separate two 
closely placed signals. As you know it is a calculated value based on the
plot of Output power in dBm vs. Input power in dBm. It cannot be 
measured like selectivity.

The IP3 really tells us how well two signals 3-5 kHz apart can be 
copied. Tom's values are good enough for me.

This device replaces an ICE 160 only receive preamplifier.

73,

John, W4NU
K4JAG (1959 to 1998)

On 8/24/2012 4:19 PM, ZR wrote:
> Why do you feel it is the best?
>
> Without knowing the circuit of the limiter I can just surmise that it 
> uses diodes or other non linear device to clip the input above a 
> certain level. Try it ahead of the preselector where the signal levels 
> are less.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- From: "John Harden" <jhdmd at bellsouth.net>
> To: <topband at contesting.com>
> Sent: Friday, August 24, 2012 3:44 PM
> Subject: Topband: DX Engineering Preselector
>
>
>> I just put in the above as it is the best one out there... However, when
>> I put in the Array Solutions RF Limiter/Arrestor between the preselector
>> and the K3 I get distortion in the signals. Any comments out there?
>>
>> The RX antenna is a Hi-Z 8-Circle array.
>>
>> 73,
>>
>> John, W4NU
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>>
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>
>