Look up "gain-bandwidth product".?? This amp has about +25 dB
gain. If it had 0 dB gain then it could work at its rated max
frequency.
73,
Steve AA7U
On 7/12/2024 2:49 PM, W0LEV via
groups.io wrote:
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The
ft of the '2222 is 250 to 300 MHz.? How
could that account for gain slump at 30 MHz?
Dave
- W?LEV
Thanks to Caaarlo for pointing out my long input lead
problem. I've redone the MPS2222 build plus built a second
one using 2SC5551. I've deleted the old picture and sweeps
from the folder and put new pictures showing the short
input leads and the input coupling transformer with the
shortest leads I could use. I've added a lot of info to
the folder description so be sure to click on it so it all
shows up. Reducing lead length indeed lowers the input
impedance at the 30 MHz high end, but has no effect on
loop amp actual gain. It's interesting that the MPS2222
has a slightly lower input impedance than the 2SC5551
version. (The same calibrated-out input transformer was
used for both loop amp sweeps.)
/g/loopantennas/album?id=296351
73,
Steve AA7U
