Gould J3B output fault - UK Vintage Radio Repair and Restoration Discussion Forum

mole42uk · 6th Apr 2019, 4:04 pm

Hi,
After spending some time chasing a fault in an audio amplifier, only to find it was a fault in the signal generator, I wonder if anyone has had similar?

The Gould J3B exhibits all the usual outputs (I'm using the 600Ω sockets) and the meter can be set to 0dB where it stays for each of the four frequency ranges. The output frequency is pretty close to the dial indication on all ranges. However, the output voltage is much lower for the bottom two frequency ranges, I forgot to measure it but probably about a quarter as seen on the 'scope display.

Looking at the circuit, the only parts I can see between the meter and the output terminals are the 300-0-300Ω transformers, the attenuator switches and associated padder networks. I wondered if anyone had seen a similar problem?

6th Apr 2019, 4:04 pm	#1
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,614	Gould J3B output fault Hi, After spending some time chasing a fault in an audio amplifier, only to find it was a fault in the signal generator, I wonder if anyone has had similar? The Gould J3B exhibits all the usual outputs (I'm using the 600Ω sockets) and the meter can be set to 0dB where it stays for each of the four frequency ranges. The output frequency is pretty close to the dial indication on all ranges. However, the output voltage is much lower for the bottom two frequency ranges, I forgot to measure it but probably about a quarter as seen on the 'scope display. Looking at the circuit, the only parts I can see between the meter and the output terminals are the 300-0-300Ω transformers, the attenuator switches and associated padder networks. I wondered if anyone had seen a similar problem? __________________ Richard Index: recursive loop: see recursive loop