Topband
[Top] [All Lists]

Re: Topband: Single antenna port xcvr but want to employ separatereceive

To: "James Rodenkirch" <rodenkirch_llc@msn.com>, "Top Band Contesting" <topband@contesting.com>
Subject: Re: Topband: Single antenna port xcvr but want to employ separatereceive antenna
From: "Tom W8JI" <w8ji@w8ji.com>
Reply-to: Tom W8JI <w8ji@w8ji.com>
Date: Mon, 13 Jan 2014 13:37:54 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>
I am nervous as well, Tom...hi Hi
I'm really thinking of employing a separate relay that I control with a simple switch, vice depending on the rig to switch "correctly" using a simple switch is antiquated and slow but....for certain I can control the switch over mo betta AND prevent damage to the low noise amplifier...>>>>

Everything else pales compared to sequencing.

For example, grounding unused ports is commonly thought to decrease unwanted coupling. Grounding to improve things assumes unwanted coupling is capacitive, and assumes there are no ground loops.

Having measured many dozens of switches, grounding does not mean less signal on unwanted ports. This is particularly true if the chassis or board has poor groundplane or wiring.

You'd be surprised how many commercial switches are actually worse because they ground unused contacts. :-)

73 Tom
_________________
Topband Reflector Archives - http://www.contesting.com/_topband

<Prev in Thread] Current Thread [Next in Thread>