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Old May 4th 10, 08:51 PM posted to rec.radio.amateur.homebrew
raypsi raypsi is offline
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First recorded activity by RadioBanter: Jul 2008
Posts: 242
Default VLF to UHF wideband amplifier with AGC for signal generator

Hey OM:

I know for sure MMIC's been around quite sum time. I used to make a
living selling them back in the 1980's to people building HBO boxes.
There's got to be plenty of apps out there. I mean wideband DC to
2.5Ghz 12db gain +-3db across the whole bandwidth.
There's a tonne of them out there. Mini Circuits is just one famous
manufacturer.

73 OM

de n8zu



On May 3, 3:49 pm, msg wrote:
Greetings,

I would appreciate any citations to projects (etched boards, layouts,
anything that has been tested) for a small wideband amplifier with
hi-Z input (1mV - 100mV), AGC (over full gain range), 50 ohm output,
approx. 100kHz to 440MHz bandwidth with min. 15dB gain; the intent
is to provide a low impedance, leveled output from cheap old signal
generators (for setups to measure antenna impedance, circuit Q,
manual spectrum analysis, etc.) Ideally, the AGC circuit would employ
an external level set control and three LEDs which indicate underrange,
locked and overrange respectively.

One would have thought that this would have been a popular item what
with the thousands of old Dynascan, EICO, Heathkit, etc. generators
still in the wild that have hi-Z unleveled outputs.

It could be built with discretes, but an AGC wideband IC makes sense,
such as the SL6140 (which is probably hard to find) -- recommendations
for any other device? Perhaps someone can point to some set-top box,
sat rcvr, cable tuner, etc. that may have something to use?

Thanks,

Michael