Hacker Herald RP10 mouldy Elkomolds - UK Vintage Radio Repair and Restoration Discussion Forum

Avid_Nerdlinger · 3rd Aug 2019, 3:30 pm

I'm starting on a late RP10, it powers up and tunes in to stations but is a bit quiet, possibly related to the broken ferrite rod and loose coil former on it or maybe this white stuff coming out of the top of the caps... Anybody recognise this feature? Definite replace or safely ignore? Also pictured is a plug which was floating about inside, seems to fit the earphone socket, does that look like the one supplied with the radio?

Meanwhile I'll work on the delaminating plywood on the back cover.

music-centre · 3rd Aug 2019, 3:42 pm

Yes, I would definitely replace the Electrolytics, likely to be faulty even without the white stuff coming out. The plug looks like a phono plug so not suitable for the earphone socket.
Steve.

Paul_RK · 3rd Aug 2019, 5:06 pm

There's no earphone socket - the plug as seen would originally have been supplied taped inside the set, and is the right one for the audio output socket provided for tape recording etc.. As I recall its level is independent of the volume control setting. The socket on the other side of the set is for a standard car aerial plug.

Paul

Avid_Nerdlinger · 4th Aug 2019, 12:06 am

Thanks Paul and Steve. Maybe the plug won't be any use to me but it's great that it's likely to be original after 55+ years. I'm going to assume the stuff on the caps is just dielectric coming out and I'll treat them with suspicion.

I superglued the ferrite rod and put the coil former back where it used to be according to the old tape marks but Radio 4 is still quiet. Surprised to see how the batteries are configured on this model, like positive and negative rails, +ve is drawing 11mA at 0 volume while the -ve draws 40mA - higher than expected so I'll look into that side of it tomorrow.

Andrew

crackle · 4th Aug 2019, 6:53 am

Don't throw the plug away, if it is the long reach one they are hard to come by.

Mike

Avid_Nerdlinger · 5th Aug 2019, 3:49 pm

Reader, I tweaked it. My new favourite radio now belts out superb sound from BBC Radios 4, 5 and Scotland. I checked the coil slugs for wax and they moved freely so I thought maybe these had been got at - I received this radio as part of a job lot and this was the only one with evidence of tampering in that the chassis was loose with the screws floating around along with the audio plug. I'll attempt a more thorough alignment in future (Advance E2 in the post).

The -9V rail is still drawing high current though. I'll start with the most mouldy-looking cap, C34, it might be one of these suspect devices conducting DC I suppose, the most obvious straw to clutch at anyway.

Avid_Nerdlinger · 5th Aug 2019, 4:20 pm

Also, the audio can't be turned right down, at 0 volume it is still audible.

Avid_Nerdlinger · 5th Aug 2019, 6:42 pm

Replaced the two worst electrolytic offenders but they didn't have any measurable faults.

Adjusted RV2 & RV3 (see before & after photos) as per service manual, instead of 3mA I was getting about 40mA on the RV2 link and this needed moving from near the middle to near one end. Now the currents being drawn from the batteries are near spec at 13.7mA for -9V and 9.7mA for +9V, should be 12 - 14mA on each but I'm going to quit while I'm ahead. Thanks for reading.

Andrew.

3rd Aug 2019, 3:30 pm	#1
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Hacker Herald RP10 mouldy Elkomolds I'm starting on a late RP10, it powers up and tunes in to stations but is a bit quiet, possibly related to the broken ferrite rod and loose coil former on it or maybe this white stuff coming out of the top of the caps... Anybody recognise this feature? Definite replace or safely ignore? Also pictured is a plug which was floating about inside, seems to fit the earphone socket, does that look like the one supplied with the radio? Meanwhile I'll work on the delaminating plywood on the back cover. Attached Thumbnails

3rd Aug 2019, 3:42 pm	#2
music-centre Heptode Join Date: Sep 2007 Location: Brentwood, Essex, UK. Posts: 687	Re: Hacker Herald RP10 mouldy Elkomolds Yes, I would definitely replace the Electrolytics, likely to be faulty even without the white stuff coming out. The plug looks like a phono plug so not suitable for the earphone socket. Steve.

3rd Aug 2019, 5:06 pm	#3
Paul_RK Dekatron Join Date: Nov 2003 Location: Fakenham, Norfolk, UK. Posts: 4,256	Re: Hacker Herald RP10 mouldy Elkomolds There's no earphone socket - the plug as seen would originally have been supplied taped inside the set, and is the right one for the audio output socket provided for tape recording etc.. As I recall its level is independent of the volume control setting. The socket on the other side of the set is for a standard car aerial plug. Paul

4th Aug 2019, 12:06 am	#4
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Hacker Herald RP10 mouldy Elkomolds Thanks Paul and Steve. Maybe the plug won't be any use to me but it's great that it's likely to be original after 55+ years. I'm going to assume the stuff on the caps is just dielectric coming out and I'll treat them with suspicion. I superglued the ferrite rod and put the coil former back where it used to be according to the old tape marks but Radio 4 is still quiet. Surprised to see how the batteries are configured on this model, like positive and negative rails, +ve is drawing 11mA at 0 volume while the -ve draws 40mA - higher than expected so I'll look into that side of it tomorrow. Andrew

4th Aug 2019, 6:53 am	#5
crackle Rest in Peace Join Date: Mar 2011 Location: Basildon, Essex, UK. Posts: 4,100	Re: Hacker Herald RP10 mouldy Elkomolds Don't throw the plug away, if it is the long reach one they are hard to come by. Mike

5th Aug 2019, 3:49 pm	#6
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Hacker Herald RP10 mouldy Elkomolds Reader, I tweaked it. My new favourite radio now belts out superb sound from BBC Radios 4, 5 and Scotland. I checked the coil slugs for wax and they moved freely so I thought maybe these had been got at - I received this radio as part of a job lot and this was the only one with evidence of tampering in that the chassis was loose with the screws floating around along with the audio plug. I'll attempt a more thorough alignment in future (Advance E2 in the post). The -9V rail is still drawing high current though. I'll start with the most mouldy-looking cap, C34, it might be one of these suspect devices conducting DC I suppose, the most obvious straw to clutch at anyway.

5th Aug 2019, 4:20 pm	#7
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Hacker Herald RP10 mouldy Elkomolds Also, the audio can't be turned right down, at 0 volume it is still audible.

5th Aug 2019, 6:42 pm	#8
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Hacker Herald RP10 mouldy Elkomolds Replaced the two worst electrolytic offenders but they didn't have any measurable faults. Adjusted RV2 & RV3 (see before & after photos) as per service manual, instead of 3mA I was getting about 40mA on the RV2 link and this needed moving from near the middle to near one end. Now the currents being drawn from the batteries are near spec at 13.7mA for -9V and 9.7mA for +9V, should be 12 - 14mA on each but I'm going to quit while I'm ahead. Thanks for reading. Andrew. Attached Thumbnails