Wideband RF power amplifier

[stenborg]

I have bought an amplifier on an auction that I need some help with. It is built by RF power labs, a company that doesn't exist anymore. And Google doesn't say much either.
My tests so far concludes that it at least works and gives output. Someone said I could expect 5-10W output power. My intention is to use it for immunity testing in a TEM cell.
I've attaches some photos.

Questions:
1. Have anyone seen this before? And if so have any documentation.
2. I have swept it from 1-500MHz with a -10dBm signal (0dBm seemed to overdrive it). The output is very nonlinear with peek power around 65MHz. Is this expected?
3. A sticker says 0.5-1000MHz What could be the expected band width with this construction?
4. Any further information that could be helpful.

Thanks

Per-Ola

[pienari]

I can not see what fets is in the board?.

[stenborg]

All are POLYFETs. The FET in the final stage is a F2012 and in the 2nd stage it is aF2001. 1st stage is hard to read but begins with F200.

[jonpaul]

like many CATV line amps. Millions were made.

Most like a 72 or 75 Ohm Zo.

Jon

[tszaboo]

like many CATV line amps. Millions were made.

Most like a 72 or 75 Ohm Zo.

Jon

Those are clearly 50 Ohm BNC connectors.

[jonpaul]

BNC type connectors exist in BOTH 50 and 75 Ohm versions.

Broadcast equipment has many 75 Ohm BNC, with slightly different inner conductor dim.

Eg used for Composite FM FMCX digital audio or AES2id.

 What is measured Zo 50 or 75 Ohm?

Jon

[tszaboo]

The isolation is also different for 50 and 75 ohm. This looks like 50 ohm( middle row)

[stenborg]

Hi,
thanks for helping me understand this amplifier. Regarding the impedance. What speaks for 50ohm is the company that used it before, I can hardly think why the could have the use for a 75ohm amp. But connecting its input to my VNA isn't conclusive, see attachment. It's all over the place, but at least centered around 50ohms. Maybe a 6dB attenuator on the input would be wise.

But at least the datasheet for the F2012 confirms the 5-10W expected power.

Keep up the good work!

/Per-Ola