I sample 10 sec´s and use 200 Hz BW. It is really interesting
to see how bad some radios are that way.
Some 100W radios using 12-16V final transistors really shouldn´t
be run at more then 50W output to show normal bandwith for a
SSB signal, sure is difficult to convince all FT1000MP owners
about this fact.
A two tone test might be good in some respects but it will ofcourse
not tell you the bandwith of your signal.
73 SM2EKM
------------------------------------------------------------------------
Bill Fuqua wrote:
> Ok, I just took a look at this and see where the problem is.
> With a resolution bandwidth of 3kHz the 3 order IMD products are masked by
> the real signal. For example if you should have a 14.2815 MHz signal and a
> 14.282 Signal producing 14.2825, you will not see the 14.2825 MHz signal
> because it will be a tiny bit added to the 14.282 signal in the spectrum
> analyzer's detector. What you need to do is to reduce the RBW to say 500
> Hz or a bit less and sample longer (a lot of talking)until you get the full
> spectrum filled in as you did before. And you should see a difference. In
> fact since the bandwidth of the SSB signal is only 2.5kHz or so wide to
> start with you will most likely not see any IMD products using a 3kHz
> resolution bandwidth. A 2 tone test is good because it is easier to compare
> results but there is nothing wrong with what you are doing. You in fact
> could do a infinite tone test (random noise source) and perhaps get results
> that would be easier to compare to others if they should try it.
>
> 73
> Bill wa4lav
>
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