Roberts Sovereign RP18 Lockdown 3 project 3 - UK Vintage Radio Repair and Restoration Discussion Forum

Andy 1964 · 14th Jan 2021, 6:24 pm

Just recieved a Roberts Sovereign RP18, in very nice condition. AF117s needed a good tap to bring AM into life, Russian replacements should be with me soon. VHF is silent, would that be the AF114s?

paulsherwin · 14th Jan 2021, 7:00 pm

Probably.

Here's a tip: the AF114-7 are all the same transistor. The specs are exactly the same. Mullard liked to market a range of transistors so that manufactures could order them in sets, so they gave them different numbers and quoted their characteristics selectively to make them seem different. They can all be replaced with any HF Ge transistor.

Confusingly, the AF118 really is a different transistor, but you don't find those in radios.

Andy 1964 · 14th Jan 2021, 7:25 pm

Hacker not Roberts, how do I edit my post?

crackle · 14th Jan 2021, 8:04 pm

Hopefully a mod will edit the title

Boulevardier · 14th Jan 2021, 8:21 pm

Quote:

Originally Posted by crackle

Hopefully a mod will edit the title

Especially as (as I was surprised to find) there is also a "Roberts Sovereign" to confuse further...though the "RP18" is a clue pointing to Hacker.

Mike

14th Jan 2021, 6:24 pm	#1
Andy 1964 Pentode Join Date: Jan 2021 Location: Hinckley, Leicestershire, UK Posts: 119	Roberts Sovereign RP18 Lockdown 3 project 3 Just recieved a Roberts Sovereign RP18, in very nice condition. AF117s needed a good tap to bring AM into life, Russian replacements should be with me soon. VHF is silent, would that be the AF114s?

14th Jan 2021, 7:00 pm	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,957	Re: Roberts Sovereign RP18 Lockdown 3 project 3 Probably. Here's a tip: the AF114-7 are all the same transistor. The specs are exactly the same. Mullard liked to market a range of transistors so that manufactures could order them in sets, so they gave them different numbers and quoted their characteristics selectively to make them seem different. They can all be replaced with any HF Ge transistor. Confusingly, the AF118 really is a different transistor, but you don't find those in radios.

14th Jan 2021, 7:25 pm	#3
Andy 1964 Pentode Join Date: Jan 2021 Location: Hinckley, Leicestershire, UK Posts: 119	Re: Roberts Sovereign RP18 Lockdown 3 project 3 Hacker not Roberts, how do I edit my post?

14th Jan 2021, 8:04 pm	#4
crackle Rest in Peace Join Date: Mar 2011 Location: Basildon, Essex, UK. Posts: 4,100	Re: Roberts Sovereign RP18 Lockdown 3 project 3 Hopefully a mod will edit the title