The frequency generator descrived above is an old but still working laboratory instrumend I build in the 1977 (about). With this oscillator was possible repar many radioreceivers and making the right adjustements. This device provides some AF frequencies as 455Khz for the MF groups or the 10,7Mhz carrier for the FM stages. It's very useful in the AF groups adjustments and to check the right tuning scale alignments.
 

Detailed view of the frequency tuning system. The cylinder marked with the white arrow is the Frequency Modulation assembly, the bottom variable capacitor is the Amplitude Modulation tuning assembly.

 

Enlarged internal view of the generator. It's possible to see a very ..caotic wiring made by myself during its assembling. This equipment works with a only one tube, a double triode ECF80. A stage of this tube was used as AF frequency generator, the other one to obtain a 600Hz BF note to use as signal tracer.

 

In the next years this old but useful generator was changed with a new one, a full digital controlled generator that I use actually to make the right radio-adjustments and in the radioreceivers troubleshooting.