UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Chinese 1A2 Super Regenerative FM radio kit

Philips210 · 24th Dec 2018, 12:23 am

Hi.

Further to my previous post, reference is made in the video concerning the 33uH RF chokes. He does away with the supplied chokes and winds his own on a plastic former. I checked my 33uH chokes and they appear to be low in value, approximately 20uH. Other circuit changes include replacing the 100pF capacitor (the one in parallel with the 5.1M Ohm resistor) with a 1nF type. The 20k pot appears to be replaced by a 2k resistor. The aerial coupling coil is replaced by a twisted wire capacitor, coupling the signal direct to the lower end of L2.

There is some confusion with the coil reference numbers. In some kits the aerial coupling coil is L1 and in others is U2.
Also, the tuning coil is referred to as L2 in some kits but U3 in others.

Regards
Symon

24th Dec 2018, 12:23 am	#64
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: Chinese 1A2 Super Regenerative FM radio kit Hi. Further to my previous post, reference is made in the video concerning the 33uH RF chokes. He does away with the supplied chokes and winds his own on a plastic former. I checked my 33uH chokes and they appear to be low in value, approximately 20uH. Other circuit changes include replacing the 100pF capacitor (the one in parallel with the 5.1M Ohm resistor) with a 1nF type. The 20k pot appears to be replaced by a 2k resistor. The aerial coupling coil is replaced by a twisted wire capacitor, coupling the signal direct to the lower end of L2. There is some confusion with the coil reference numbers. In some kits the aerial coupling coil is L1 and in others is U2. Also, the tuning coil is referred to as L2 in some kits but U3 in others. Regards Symon