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Re: [Amps] RF probe and SSB (may be a little OT)

To: "Bob Tortajada" <n6ri@rtort.com>,"W2RU - Bud Hippisley" <W2RU@frontiernet.net>
Subject: Re: [Amps] RF probe and SSB (may be a little OT)
From: "k7fm" <k7fm@teleport.com>
Reply-to: k7fm <k7fm@teleport.com>
Date: Sun, 12 Mar 2006 08:02:13 -0800
List-post: <mailto:amps@contesting.com>
>I have a Tek-475, just no probes or manual. The manual I can get from
>the internet, but the plethora of knobs and buttons on the 475 has
>humbled me. To be honest, I have no idea what most of them do.

>I know I need a RF probe, but not sure if that is something easy to
>build or buy.

The 475 is a nice scope.  I have one sitting about 10 feet away.  It has a 
200 MHz bandwidth.

You do not need any special expensive probes to check linearity of the 
amplifier.  "Amateur Single Sideband", originally published by Collins Radio 
has a nice envelope detector circuit which can be built quickly.  A detector 
is placed on the output of the amp and another one at the input.  Each unit 
uses 2 capacitors, 2 rf chokes, 1 diode and 1 resistor.  The output of each 
would go through shielded cable to a bnc for connection to the scope.

Although the scope may look frightening, it can be learned rather quickly. 
Certainly not as complex as a modern multi-memory transceiver that has 25 
different uses for the same buttons.  I need to get the manual out and sit 
dazed for many minutes before completing a simple task on my uhf/vhf rig. 
Last time I went out on a hidden transmitter hunt and pulled over to try to 
figure out how to use the attenuator mode of the squelch control.  I got the 
manual out and it referred to a control that was not on my radio.  So, then 
I had to page through the entire book to figure out how I could get to that 
menu.  In the meantime, a police officer stopped to see if I needed help.  I 
told her I did.  I also explained that the fellow out in the field with a 
small yagi also needed help, because he was really lost.  As she was 
leaving, she noted that my license plate was 3 months expired.  The good 
news is that she also noted that I have a County Sheriff's Search and Rescue 
tag on my car so she did not bother giving me a ticket.  But, I can operate 
the 475 without a manual.

The 475 would be frightening if it only had 5 controls.

73,  Colin  K7FM 

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