Well, everything is nonlinear to sone degree, but that¡¯s pedantry and not useful engineering. We¡¯re looking at a claimed 20dB degradation in intercept. That¡¯s well beyond anything that can be attributed to a proper cable/connector system.
Cheers
Tom
Sent from my iThing; please forgive the typos and brevity
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On May 14, 2023, at 09:34, G8HUL <g8hul@...> wrote:
?I would disagree with Tom regarding " Properly functioning cables and connectors" not being non-linear. There is always some non-linearity, it just depends on the level. Even the slightest amount of contact resistance in the braid or at connector interface will cause unwanted products, perhaps at an extremely low level but they will be there.
There is a lot of info on the subject on the web, but here is one example:
< >
Regards
Jeff G8HUL
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Tom Lee
Sent: 14 May 2023 12:28
To: [email protected]
Subject: Re: [Test Equipment Design & Construction] Low noise high reverse isolation low distortion RF Amplifier
I agree with Jeff. Properly functioning cables and connectors are not nonlinear and thus cannot produce the effects that Lankford reports (assuming that he has achieved a proper match to eliminate the obvious length-dependent effects). A 20dB degradation in intercept sounds like the result of a tarnished connector to me.
-- Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
On 5/14/2023 01:42, G8HUL wrote:
I think that the coax cables, and connectors, should be investigated in isolation, Non-linearities in cables and connectors are a well-known phenomenon.
73
Jeff G8HUL
-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Jeff Green
Sent: 14 May 2023 01:19
To: [email protected]
Subject: Re: [Test Equipment Design & Construction] Low noise high
reverse isolation low distortion RF Amplifier
The best I can do is to refer you to this web page PDF, Dr. Lankford's concept of best small antennas.
,%20LW,%20And%20SW%20rev%202.pdf
Here is some of the text"
"While studying active whip intercepts some time ago I discovered,
much to my amazement, that long coax (50 feet) lead often degrades 2nd
order intercepts of active whip antennas by 20dB
