UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 0.1-2000 MHz Wide Band Amplifier ~£4

Skywave · 22nd Oct 2018, 11:32 pm

Bazz4CQJ: Quite likely. As you know, quite some time ago I set about designing a wide-band R.F. millivoltmeter (2 MHz - 100 MHz) - which, incidentally, is still on the 'back burner'. At one stage during development, I had substantial attenuation at about 80 MHz that I couldn't account for, nor detect the reason why - until I went searching with my 1 GHz spectrum analyzer. I found substantial oscillation at approx. 730 MHz, over a bandwidth of about 100 kHz! That was cured by increasing capacitive decoupling plus a few judiciously-placed ferrite beads.

Al.

22nd Oct 2018, 11:32 pm	#22
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: 0.1-2000 MHz Wide Band Amplifier ~£4 Bazz4CQJ: Quite likely. As you know, quite some time ago I set about designing a wide-band R.F. millivoltmeter (2 MHz - 100 MHz) - which, incidentally, is still on the 'back burner'. At one stage during development, I had substantial attenuation at about 80 MHz that I couldn't account for, nor detect the reason why - until I went searching with my 1 GHz spectrum analyzer. I found substantial oscillation at approx. 730 MHz, over a bandwidth of about 100 kHz! That was cured by increasing capacitive decoupling plus a few judiciously-placed ferrite beads. Al.