Hello All-
Awhile back I posted this message. I didn't find anyone who had
tried this, but I did get some useful insights as to why this should be
approached with caution (rise time, linearity, etc).
I went ahead and tried it myself and can report that it works fine - at
least for my purposes. The primary limitation is that you need to be
interested in nuclei in the FM band, but there are a number that are
close to that for 400 MHz NMRs such as we have here at SOU - e.g. 29Si,
13C, 27Al; 29 Si looks like it would be outside of the FM band, but
works fine with this amplifier.
The rise time is not at all an issue and the amplifier reproduces the
input pulse well. The linearity is not exactly a "non-issue": the amplifier
is "pretty linear" from 50 - 500 watts (I have not tested it above 500
watts as my probe arcs at those powers). I can't vouch for linearity below
50 watts, but from the spec sheet it doesn't look too linear in that region.
The amplifier doesn't appear to be excessively noisy with no input.
In conclusion, this is one option to gain higher rf power on a liquids
instrument if it covers the range you are interested in and you aren't
"super concerned" about linearity at lower powers.
All the best to everyone.
Tom Pratum, Southern Oregon Univ.
> On Sep 5, 2022, at 12:49 PM, Tom Pratum <tkp9551_at_gmail.com> wrote:
>
> Hello All and Happy Labor Day:
> I am wondering if anyone has used a commonly available FM pallet
> amplifier module for the final stage of their NMR transmitter? They do
> indeed have limited frequency range (FM: 88 - 108 MHz), but they do
> cover the desired frequencies in my case. They are also not normally
> entirely linear, which may or may not make a difference in my case.
>
> Very much appreciate hearing of any experiences that have been had.
>
> Thanks in advance.
>
>
> Tom Pratum
> Southern Oregon University
>
Received on Wed Nov 16 2022 - 01:14:39 MST