|
Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
|
Thread Tools |
19th Mar 2006, 12:27 am | #1 |
Retired Dormant Member
Join Date: Aug 2003
Location: Stansted Essex
Posts: 263
|
Hacker Sovereign RP18
Hi all.
I have been spending some time on my Hacker Sovereign RP18, which was recently aquired from Paul Stenning, (thanks Paul). The fault report from Paul, was that it did nothing but pop when switched on. So first things first. After hooking the set up to a bench PSU, I monitored the input current, 300mA and rising (ouch, these sets shouldn't take any more than about 100mA when playing very loudly). After removing the chassis from the cabinet, I decided to check the operation of the amplifier module first, this it seems was the first casualty,and responsible for the excessive current consumption. Capacitor C14 was very leaky (almost short circuit). This, along with all the other electrolytics was replaced. They were all in a bad way. After setting the quiesent current (4mA), and mid point voltage, (8.85V). The module performed very well. Now to the rest of the set. After giving all the pots and band switches a good dose of switch cleaner, I was rewarded with, very little infact . AM was dead, and FM very very weak. The current was now about 24mA which is about right. These sets use the dreaded AF11x range of transistors. So the 3 in the AM IF Strip were given the charged capacitor treatment, all recovered well. (I may replace with BF 450,s should they fail again). After a quick re-alignment using my Radio Bygones wobulator, AM now works wonderfully. Again the poor FM Performance was down initially to bad AF114's (there are 4 of them in these sets). These were all replaced with AF124's, following this the IF strip was very much alive, (too much in fact ), it was very very unstable. Replacing the electrolytics did little to help the situation. The fault was eventually traced to a faulty diode CR4 which lives in the AGC line. I found this after checking the voltage on pin 3 of the tuner, (Indicated as a test in the service manual). This should be 1.5V WRT the +ve rail on the IF strip, mine was at 3.5v, and could not be adjusted with R28 as indicated, replacing CR 4 cured this, and the instability. After re-alignment the set is now performing very well indeed. I may just need to replace the volume control, as it is rather noisy. Although a real challenge to repair, these are IMO the best sounding Hacker's. I think they sound better than all the Sov II's and RP 38's. Next, on to the cabinet, but first, a well deserved Pete |
19th Mar 2006, 10:17 am | #2 |
Nonode
Join Date: May 2005
Location: Godalming, Surrey, UK.
Posts: 2,593
|
Re: Hacker Sovereign RP18
Hello Pete,
Gosh, you certainly know your way around transistor radios ! I've never bought a dead Hacker, they've always arrived working after little effort but then I haven't got an RP18 Sovereign with those AF11* transistors, but I must find one if they sound that good ! I look forward to seeing the cosmetic restoration. Howard Last edited by howard; 19th Mar 2006 at 10:25 am. |
19th Mar 2006, 1:48 pm | #3 | ||
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,864
|
Re: Hacker Sovereign RP18
Well done Pete
Quote:
Quote:
Nick. |
||
19th Mar 2006, 1:56 pm | #4 | |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,864
|
Re: Hacker Sovereign RP18
Quote:
Common faults to look for are:
|
|
20th Mar 2006, 2:50 pm | #5 |
Retired Dormant Member
Join Date: Aug 2003
Location: Stansted Essex
Posts: 263
|
Re: Hacker Sovereign RP18
As Nick says, they are definately not the easiest sets to work on.
Fortunately of all of these that I have restored, I have never had a fault in the VHF front end, as that would be a real to get at, there are no AF11x's in there though, thankfully. I have almost finished the cosmetics now, so will post pictures later. Thankfully the cabinet is in good condition anyway, although I did have to reglue the white beading around the front and rear panels, as well as straighten out the grille a little. One thing I did find a little strange, on this set the rear grille is red, . It certainly looks original though, and there is no evidence of it being replaced, or refixed at any time. Pete |
20th Mar 2006, 8:10 pm | #6 | ||
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,864
|
Re: Hacker Sovereign RP18
Quote:
Quote:
Nick |
||
21st Mar 2006, 9:42 pm | #7 |
Retired Dormant Member
Join Date: Aug 2003
Location: Stansted Essex
Posts: 263
|
Re: Hacker Sovereign RP18
Hi all.
Finally finished the set now. Works beautifully, listening to Classic FM , as I took these photos. The sound quality is well worth the effort. A most enjoyable restoration. Pete |
21st Mar 2006, 10:07 pm | #8 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,864
|
Re: Hacker Sovereign RP18
Looks as good as it sounds, Pete
|
21st Mar 2006, 10:45 pm | #9 |
Heptode
Join Date: Jun 2004
Location: Ilkley, West Yorkshire, UK.
Posts: 656
|
Re: Hacker Sovereign RP18
Great job Pete, it really looks the business.
One of the nice things about this forum is the encouragement and inspiration one gets from seeing a job well done. I must put mine at the front of the 'queue'. rgds Colin |
24th Mar 2006, 7:02 pm | #10 |
Retired Dormant Member
Join Date: Aug 2003
Location: Stansted Essex
Posts: 263
|
Re: Hacker Sovereign RP18
Thanks for the comments guys.
Yes I am very pleased with it. Pete |
3rd Apr 2006, 8:54 pm | #11 |
Nonode
Join Date: May 2005
Location: Godalming, Surrey, UK.
Posts: 2,593
|
Re: Hacker Sovereign RP18
Hello Peter,
That is an excellent cosmetic restoration, well done indeed. And I have to say that the RP18 is a slightly nicer looking radio than the later Sovereign IIs I must get one ! Howard |
4th Apr 2006, 8:55 am | #12 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
|
Re: Hacker Sovereign RP18
Nice one, Pete, and I must admit that it has a better scale design than the RP25 that I just did.
__________________
Mike. |