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Using a scope as a station monitor	Reply
by VE6KLJ on June 4, 2008	Mail this to a friend!
I have a question, I see all these station monitiors out there, but I have a 50mhz scope. Is it possible to use it as a station monitor.. do I take the IF output on the radio and look at it with the scope? Rather curious as to how this works... Posted in homebrew.. just not sure where else to post 73, VE6KlJ

RE: Using a scope as a station monitor	Reply
by W5FYI on June 5, 2008	Mail this to a friend!
I believe what you need is called a panadapter. It sweeps the IF frequency range for display on an oscilloscope. Your radio's manufacturer may offer one as an accessory for your particular rig, and you should be able to use your own oscilloscope to complete the system.

RE: Using a scope as a station monitor	Reply
by VE6KLJ on June 5, 2008	Mail this to a friend!
Thanks, Yea I have been doing some research and it seems that the "old school" station monitors sample off the radio's RF output, and you can purchase devices that do this. Really, I just wanted a way to be sure I'm not splattering my signal (And its good to be able to monitor it anyway). I think I will look into one. Cheers, VE6KLJ

RE: Using a scope as a station monitor	Reply
by W5FYI on June 5, 2008	Mail this to a friend!
An easy way is to just ask whoever you're in QSO with to check for splatter. He should be able to do it for free!

RE: Using a scope as a station monitor	Reply
by WB2WIK on June 5, 2008	Mail this to a friend!
Big difference between a scope and a panadapter. If you only want to check your transmitted signal, you don't need any receiver connection at all. Just sample a bit of RF from your transmitter and feed it into the scope. A resistive divider works well for this, as it will have flat frequency response (as compared with a capacitive divider or just a coupling capacitor). Now, whether what you "see" will be of any real value is another issue! It takes quite a bit of distortion to be clearly evident on a typical 4" or 5" scope, and of course the scope won't tell you anything about IMD (intermodulation distortion) at all -- that takes a receiver (spectrum analyzer), as well as a complex, controlled, low-distortion modulation source. WB2WIK/6

RE: Using a scope as a station monitor	Reply
by VE6KLJ on June 5, 2008	Mail this to a friend!
Interesting. really yes, i'd want to see my transmitted signal. So those old station monitors you see on ebay etc, how do they work? I notice they must sample RF off the radio's output as there's an antenna line in and out on them...

RE: Using a scope as a station monitor	Reply
by WB2WIK on June 6, 2008	Mail this to a friend!
Yes, that's what they do. The Heath SB-610 is a great example (not a good scope, but very easy to set up since the sampler was right inside the unit, with SO-239s in and out, and a "power adjustment" switch to sample more or less signal, depending on the power level being used). WB2WIK/6

RE: Using a scope as a station monitor	Reply
by KF7SN on June 20, 2008	Mail this to a friend!
What you need is a RF SAMPLER, please check out this web site for such a thing. Just rember don't put full power of 100 watts into it or you may blow the 1/4 watt 50 Ohm resistor. http://www.qsl.net/k6ls/rfsampler.html 73, KF7SN Geary Yahoo Group Owner and Founder of: http://groups.yahoo.com/group/HeathKit_HFAmps, and http://groups.yahoo.com/group/Kenwood_TMV-71A

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