Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: kagliostro on March 11, 2015, 11:20:08 am

Title: How to measure Impedance - Bandwidth - Efficiency of an OT - Here the solution
Post by: kagliostro on March 11, 2015, 11:20:08 am

http://www.crystal-radio.eu/entrafometing.htm (http://www.crystal-radio.eu/entrafometing.htm)

K

Title: Re: How to measure Impedance - Bandwidth - Efficiency of an OT - Here the solution
Post by: PRR on March 11, 2015, 08:54:35 pm

> Adjust the potentiometer R1, so R1+Rg is equal to the input impedance of the transformer.

While the "matched" condition is good to know, in many cases the transformer will be used UN-matched.

With solid-state drivers, the source impedance may be nearly zero.

With power pentodes, the source impedance is often 10 times the reflected load impedance.

For these cases you would measure the Frequency Response using the intended impedances.

Title: Re: How to measure Impedance - Bandwidth - Efficiency of an OT - Here the solution
Post by: kagliostro on March 12, 2015, 09:15:52 am

In this days I'm trying to collect info about OT measurement

I would like to measure the bandwidth of an OT I've

Someone can report better methods than that indicated on the link ?

Thanks

Franco