Re: Fwd: New Sherwood report

Posted by Joe Subich, W4TV-4 on Dec 03, 2010; 5:59pm
URL: http://elecraft.85.s1.nabble.com/Fwd-New-Sherwood-report-tp5793377p5806129.html


 > Another way of investigating is with a spectrum analyzer - and for
 > investigation of a transmitted signal on one band, it does not have to
 > be expensive (but must be homebrewed to be inexpensive).

Another solution for simple spectrum analysis is SDR-IQ and the CP-1
directional coupler are very good for looking at transmitter outputs
while the SDR-IQ and an active antenna like the one from Clifton
Laboratories (K8OZA) are good for "off air" use.

While this may not be as inexpensive as a homebrewed solution, it
can be very cost effective if one already owns the SDR-IQ for other
purposes.

73,

    ... Joe, W4TV


On 12/3/2010 11:41 AM, Don Wilhelm wrote:

>    Paul and all,
>
> Another way of investigating is with a spectrum analyzer - and for
> investigation of a transmitted signal on one band, it does not have to
> be expensive (but must be homebrewed to be inexpensive).  See the
> implementation by G4AON at http://www.astromag.co.uk/ssa/
>
> It is quite a nice narrowband spectrum analyzer - you can see the
> display using Spectrogram or Spectrum Lab or most any other audio
> spectrum analyzer running on the shack's soundcard equipped PC.
>
> You are correct, a 'scope is the most useful tool for measuring timing
> and amplitude.
>
> 73,
> Don W3FPR
>
> On 12/3/2010 10:55 AM, Paul Christensen wrote:
>>> Why, yes IMO the K3 clicks too much.
>> Jim,
>>
>> If you're experiencing clicks with your K3, you really need to investigate
>> with a scope.  At the risk of pontificating, every station should have a
>> scope to monitor the transmit waveform.  It can also be used to effectively
>> monitor T/R sequencing times when using an external amp.  I suspect many
>> stations are hot-switching their amps and don't even know it until a T/R
>> relay's contacts fuse and the relay fails.  Cost is no longer an excuse.
>> Anyone who can afford a K3 or FTdx5K can own a scope.  Good quality used
>> scopes can be purchased on the surplus market between USD $100-200.
>>
>> If I may make a plug for N8LP, he's got a forthcoming product that addresses
>> my pontification nicely:
>>
>> http://www.telepostinc.com/LP-500.html
>>
>> Cost will be more than a used oscilloscope, but it looks like his product is
>> concentrated on what we need for monitoring rather than general bench work.
>> Design and cosmetics appear to be commensurate with the Elecraft K3.
>>
>> Paul, W9AC
>>
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