Hacker Sovereign RP18 - UK Vintage Radio Repair and Restoration Discussion Forum

G0PKH - Pete · 19th Mar 2006, 12:27 am

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

howard · 19th Mar 2006, 10:17 am

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

Nickthedentist · 19th Mar 2006, 1:48 pm

Well done Pete

Quote:

Originally Posted by Pete_Hillyer

Capacitor C14 was very leaky (almost short circuit). This, along with all the other electrolytics was replaced. They were all in a bad way.

Yes, I find that there are often so many faulty electrolytic caps in Hackers of this vintage, it pays to replace the lot, regardless of what purists would think.

Quote:

Originally Posted by Pete_Hillyer

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.

Totally agree, they're not nearly as engineer-friendly as the Sov IIs and Heralds, both from an access and a spares point of view, e.g. the speaker is a 30 Ohm unit.

Nick.

Nickthedentist · 19th Mar 2006, 1:56 pm

Quote:

Originally Posted by howard

Gosh, you certainly know your way around transistor radios ! I've never bought a dead Hacker, they've always arrived working...

About 50% of mine have been DOA, but most are very easy to understand, largely due to the fact that the AM, FM and Audio parts of the circuit are on separate PCBs, and that the service manuals are superb.

Common faults to look for are:

Battery terminals (e.g corrosion between the bit that attaches to the battery, and the solder tag)
Sockets (headphone and tape input) - corrosion or using the wrong plug can cause the normally-closed contacts to stay open, resulting in no sound
Dry joints in the VHF tuner head, leading to an intermittently dead set (because the tuning suddenly shifts up or down the dial, then the interstation muting kicks in and silences everything).
Faulty electrolytics (the smoothing ones on the FM and AM boards can go low value and leaky, robbing the boards of their supply voltages)
AFXXX transistors (obviously)!

Nick

G0PKH - Pete · 20th Mar 2006, 2:50 pm

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

Nickthedentist · 20th Mar 2006, 8:10 pm

Quote:

Originally Posted by Pete_Hillyer

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'm ashamed to say that I cannibalised an RP18 for spares a few years ago, merely because some twit had been messing around with the tuner (a German, Gorler-brand one, I think), and access for repair/testing looked too involved. The speaker is in use in my kitchen VHF Herald, and the amp board and dial have been sold/donated to people on this forum, so at least it didn't die in vain.

Quote:

Originally Posted by Pete_Hillyer

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.

Maybe they were short of black ones at the factory (the Hacker Dealer Letters I've got imply that their were perpetual problems with components suppliers), but I think it's more likely that yours is a replacement, possibly when the set was still quite new. Colourful, though

Nick

G0PKH - Pete · 21st Mar 2006, 9:42 pm

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

Nickthedentist · 21st Mar 2006, 10:07 pm

Looks as good as it sounds, Pete

Colin · 21st Mar 2006, 10:45 pm

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

G0PKH - Pete · 24th Mar 2006, 7:02 pm

Thanks for the comments guys.

Yes I am very pleased with it.

Pete

howard · 3rd Apr 2006, 8:54 pm

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

Mike Phelan · 4th Apr 2006, 8:55 am

Nice one, Pete, and I must admit that it has a better scale design than the RP25 that I just did.

19th Mar 2006, 12:27 am	#1
G0PKH - Pete 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
howard 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.

20th Mar 2006, 2:50 pm	#5
G0PKH - Pete 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

21st Mar 2006, 9:42 pm	#7
G0PKH - Pete 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 Attached Thumbnails

21st Mar 2006, 10:07 pm	#8
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Hacker Sovereign RP18 Looks as good as it sounds, Pete

21st Mar 2006, 10:45 pm	#9
Colin 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
G0PKH - Pete 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
howard 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
Mike Phelan 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.