[HomeBrew] Re: HomeBrew digest, Vol 1 #136 - 1 msg

[LARRY JONES]

Hi Chuck...
     What you need is a directional coupler. This device is connected in
line with a dummy load and has a sampling port that is approximately 20-30
db down from the original signal level. If you do a search of the internet
you may find info on how to build your own. They are not difficult to
construct.

Larry  <><   N5OSG
Garland  Tx
: Today's Topics:
:
:    1. inline attenuators? (Chuck Lippmeier)
:

:
: Message: 1
: From: "Chuck Lippmeier" <csl@world.std.com>
: To: <homebrew@mailman.qth.net>
: Date: Sat, 31 Aug 2002 10:53:49 -0400
: Subject: [HomeBrew] inline attenuators?
:
: How are inline attenuators made?=20
:
: I just bought a spectrum analyzer on e-bay and I thought, "oh boy, what =
: can I measure?". It occurred to me that my 2m puts out 50W into 50 ohms =
: and it might be interesting to look at that signal. I looked up the =
: input capability of my spectrum analyzer and it is 30dBm. I did the math =
: and 30dBm is around 1W. Lesson: don't connect the 50W output of my 2m =
: rig directly to the input of my spectrum analyzer. Ok, I said, how can I =
: look at this signal? Well it occurs to me that Weinchel sells in line =
: attenuators. I've seen and used them for other purposes and they look =
: like hot dogs with fins. I looked them up on the web page and the Model =
: 48 would do the job. I figured I'd like a 30dB attenuator that could =
: handle >50W. A 100Wer would do it. I called Weinchel and they say =
: that'll be approx $500. I can't afford that. Actually I was thinking =
: they would say maybe $50 max.=20
:
: I guess, if I'm going to do this, I'll have to build one myself. Somehow =
: though, I don't think this is as simple as buying a 100W 50ohm resistor =
: and putting it across the output coax conductors with the spectrum =
: analyzer also hooked up to the output. Do any of you know how to do =
: this?
:
: Chuck=20
: KB1HTO
:
: