"John L Stewart"
Go to this link- www.hparchive.com
to see the HP 207A Wide Range Oscillator listed under the equipment
heading.
20 Hz to 20 KHz in one twist of the dial. Uses a modified Wein Bridge.
** OK - I have had a look at the manual now and that is one cleverly
designed piece of kit.
Getting a 1000:1 frequency range from a tuning gang oscillator is quite a
feat and HP make it look so easy.
The four tube sustaining amplifier and output buffer is a winner too.
Shame the unit appears to be quite rare.
..... Phil