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Re: Topband: Preamp for 160

Subject: Re: Topband: Preamp for 160
From: "Dan Zimmerman N3OX" <>
Date: Mon, 19 May 2008 22:51:10 -0400
List-post: <">>
>Will these connector types cause allot of loss to the incoming signal or do I 
>just solder on the >coax as though they were pl-259's

No measurable loss will occur if you just solder cheap radio shack RCA
connectors to the coax or use adapters to some more common RF
connectors.   I doubt you'd get measurable loss if you taped the coax
into the connectors ;-)

Here's a photo I took of a chain of 18 or so adapters, including some
very cheaply made phono adapters, passing 100W at 1.8MHz with not even
a watt of noticeable loss:

So the total loss, including a mating pair of cheap phono connectors,
is less than 0.04dB.

Even if the connectors *were* lossy (which they never noticeably are)
little bit of loss doesn't matter so much in a receiving system.  Your
20dB is unlikely to be exactly the amount you need to limit on the
external noise floor, so you'll probably  have a little surplus gain

There might be some really cheap phono connectors that will be
mechanically unreliable and become intermittent, so spending a couple
bucks for decent connectors is probably still worth it.

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