UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Two or three IF stage Chinese radio kits.

Neil Purling · 31st Dec 2016, 5:41 pm

Can anyone read the text and tell me exactly what is important about R4?
I have uncovered a 9018-2 kit elsewhere. The circuit & component values are the same. The only differences between the S66-E, HX6-B and 9018-2 is the printing of the PCB and case styles.
The reference to R4 may say: "When the amplifier gain is low, you can change the resistance R4, the sound will improve".
It does not say anything beyond that but I assume that the next values above 30K will start to cut the collector current. I must have got some particularly high gain transistors and the signal needs attenuating.

31st Dec 2016, 5:41 pm	#11
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,086	Re: Two or three IF stage Chinese radio kits. Can anyone read the text and tell me exactly what is important about R4? I have uncovered a 9018-2 kit elsewhere. The circuit & component values are the same. The only differences between the S66-E, HX6-B and 9018-2 is the printing of the PCB and case styles. The reference to R4 may say: "When the amplifier gain is low, you can change the resistance R4, the sound will improve". It does not say anything beyond that but I assume that the next values above 30K will start to cut the collector current. I must have got some particularly high gain transistors and the signal needs attenuating.