the h4 (or other "older" nanovna models) have a clock up to 300 megs and up to 900megs or 1.5ghz is done with third or fifth harmonics
the newer V2, saa2n etc.. are made with a clock up to 4.4ghz or a clock up to 6ghz (litevna62/64)
so they work much better in UHF or higher
dg9bfc sigi
Am 06.11.2024 19:55 schrieb Stan Dye <standye@...>:
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On Wed, Nov? 6, 2024 at 07:37 AM, Ray Lulling wrote:
I thought the H4 had both chips.
No. All of the vna models I am aware of have only one.? The MS vs SI chip
is really an 'available supply' issue rather than a performance one.? The
firmware selection is to accommodate whichever one is in your device.
And as the previous poster said, if you primarily want to work at
850MHz-1GHz, you would probably be happier if you pay a bit more and
choose the litevna64 or one of the V2 models that are designed for higher
frequencies.
Yes, the H4 will 'work' up beyond 1.5GHz - but its performance drops off
significantly as you go up in frequency.? Its best performance is up to
300MHz, and it still works reasonably well up to 800 or 900MHz (its
original spec'd top frequency) - but regardless of which chip it has, all
of these higher frequencies have a much decreased dynamic range.
The units units designed and advertised for 4-6GHz have many of the same
issues at their highest frequencies, but work much better than the H4 at
800-900MHz and in the low GHz range.
