Fw: [Test-Equipment] No luck with sweep markers

[RJ Mattson]

Tnx Ron for the reply
>   Does the sweep generator have an output for the 'scope's vertical input
>  and a "demod out" input connector?

NO - The sweep gen has output for the scope horiz amp and swept rf output.

>   The marker needs to be "beat" with the sweep, low passed and mixed then
> added after the output of the demodulation.

>From an article, I need the circuit probably called a "Post Injection Marker 
Adder" It would blend the demodulated trace with RF markers and sends the 
mix to the scope vertical input. Any ideas for a circuit or purchase?
bob...w2ami
>    Ron  KA4INM
>
----- Original Message ----- 
From: "Ron Youvan" <ka4inm at tampabay.rr.com>
To: "RJ Mattson" <rjmattson at hvi.net>
Sent: Wednesday, January 25, 2006 10:35 PM
Subject: Re: [Test-Equipment] No luck with sweep markers


> Hi   RJ Mattson bob w2ami:
>> I am successfully sweeping a 455 kHz IF strip with a Wavetek 134 and T935 
>> scope.
>> The scope waveform trace looks typical for 455 kHz with a 10x probe or 
>> demod probe.
>> With an external adjustable rf generator I am trying to inject a marker 
>> to determine the center freq, band width, etc.
>> As I move the marker sig gen through 455 kHz, all I am seeing is a 
>> sinewave superimposed all over the scope bandpass outline trace - no pip 
>> marker.
>> I have tried different injection points, sweep widths and sweep time with 
>> no result.
>> Any suggestions?
>> Are injected markers only visible with higher frequencies such as wide 
>> video IF's?
>> I read an article where they suggest the best way to use markers is with 
>> a "post injection" circuit ?
>