UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Attenuators

G6Tanuki · 28th Nov 2017, 8:51 pm

Purely-resistive attenuators, matched to the ssource and sink impedances [assuming these are frequency-independent] are really rather simple.

If the source/sink impedances are inconsistent, these can be 'tamed' by making the attenuation something like 10dB or so - downstream of that you'll really only be seeing the characteristic-impedance of the attenuator, not the source.

Slug the incoming side with a load-resistor that can easily dissipate whatever the source can throw at it.

In my experience the biggest problem with attenuators has been dissipating tens/hundreds of Watts of peak RF energy with 50,000:1 duty-cycles.

"It's only averaging a Watt; what's complicated?!"

28th Nov 2017, 8:51 pm	#4
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,998	Re: Attenuators - theory and the design of. Purely-resistive attenuators, matched to the ssource and sink impedances [assuming these are frequency-independent] are really rather simple. If the source/sink impedances are inconsistent, these can be 'tamed' by making the attenuation something like 10dB or so - downstream of that you'll really only be seeing the characteristic-impedance of the attenuator, not the source. Slug the incoming side with a load-resistor that can easily dissipate whatever the source can throw at it. In my experience the biggest problem with attenuators has been dissipating tens/hundreds of Watts of peak RF energy with 50,000:1 duty-cycles. "It's only averaging a Watt; what's complicated?!"