Armstrong 526 receiver transistor part - UK Vintage Radio Repair and Restoration Discussion Forum

Goodizzy · 11th Sep 2018, 8:49 pm

Evening,

I purchased an Armstrong 526 receiver and had it shipped to the US. It was packaged fair, but not great, and as a result I had a few chipped veneers and other minor exterior case issues which I have sorted.

However, upon taking the receiver out of the case I noticed that a copper piece (see image) had come loose and was settled in the tuner section of the receiver, away from anywhere it probably should go. I imagine it rattled off of a transistor?

There is another like it in what appears to be the power board. Also, below is another transistor similar in size and appearance to the one with the heatsink? Sleeve. Is this where this belongs? Should I just carefully slip it back over the transistor can? Many thanks for any assistance,

Chris

Goodizzy · 11th Sep 2018, 8:51 pm

Image of copper sleeve-

paulsherwin · 11th Sep 2018, 8:55 pm

I don't know this receiver or have a schematic. However, that just looks like a clip on heatsink. They do sometimes work loose.

What is the transistor type that you think the heatsink fits?

roffe · 11th Sep 2018, 9:56 pm

Could be from the power amplifier board.There are three heatsinks shaped like this.
http://www.audiomisc.co.uk/Armstrong...s/A14board.gif

Goodizzy · 11th Sep 2018, 11:22 pm

I believe you are right in regards to its purpose. It looks to be a slip on heatsink sleeve.

I should have posted this earlier, but this link has pertinent diagrams- http://www.audiomisc.co.uk/Armstrong/500/500diags.html

The Z.17 power board is the only board I see that has another one of these heat sinks on it, despite the diagrams indicating otherwise. (Maybe I am missing a few?). Neither channel's power amplifier boards have heatsink a over can transistors.

I will try rotating the chassis around to see if I can determine what is written on the other can transistors on the Z.17 power board. But without pulling the card itself, I may not be able to see it. The power board contains fuses, rectifier, etc

Finally I should add that this version of the receiver looks to have (2) AL100s and (1) AL120 in the power section. Produced late 60s - 1972.

buggies · 12th Sep 2018, 10:43 am

Attached pics show 2 heatsink clips on the power supply board.
Would you believe I used the photoshop "add dust" effect?

Goodizzy · 12th Sep 2018, 5:17 pm

Thanks George, that cleared it up. It was the suspected transistor.

This receiver looks faurly clean inside but I will give it a blow out with duster..

Many thanks all

Goodizzy · 13th Sep 2018, 4:02 pm

I apologize for necroing the thread but I have found one more part that could have come dislodged during shipping. It is the lamp in the white base, in the picture.

It is sitting against the back of the tuner section. And the brass colored bar isn't connected to the lamp.

Is it possible this is just where it was put by the tech building? All components look original to my eyes. I'd like to correct it before I put this back in the case.

buggies · 13th Sep 2018, 5:38 pm

The lampholder should be slid on to a metal bar at the left hand end of the dial so it illuminates the meter from behind.

paulsherwin · 13th Sep 2018, 5:38 pm

The plastic holder should slide into a metal bracket somewhere, maybe the one to the right of the picture?

(Crossed)

Goodizzy · 13th Sep 2018, 9:03 pm

Thank you guys, it looks to have come loose during transport. I will put back together and try turning it on tonight after dinner.

Grr! I really HOPE there is no electrical damage as a result of the postal service and poorer packing!

buggies · 14th Sep 2018, 7:55 pm

Mine was very reliable over most of its years of use. Only problems were noisy switches and volume control and the plug-in board connectors so all sorted fairly easily.
It has not been switched on for a decade or two now so I would be interested to hear if you find any faulty components when you test your unit

Goodizzy · 16th Sep 2018, 4:02 pm

I intended to get back to this over the weekend but was prepping for a storm that hasn't lived up to its hype. I hope to return to this over the next few days and will post any discrepancies.

Do you have a recommendation for switch/contact cleaner for the older push switches? I have a few pieces off this era's gear and all could do with a cleaning. I have used CRC in the past but would like to get something more appropriate for this older equipment.

'LIVEWIRE?' · 16th Sep 2018, 4:45 pm

I've always used Servisol Super 10 for switxh & potentiometer cleaning in equipment of various makes, models & ages. CPC stock this among a range of cleaning/lubricating products.

paulsherwin · 16th Sep 2018, 5:10 pm

Deoxit D5 seems to be the favourite (favorite?) contact cleaner in the US.

http://store.caig.com/s.nl/sc.2/category.188/.f

It's a bit pricey though, and most contact cleaners should be fine. Don't use (original) WD40, though there is a WD40 branded specialist contact cleaner which should be OK.

Goodizzy · 16th Sep 2018, 10:57 pm

Ah! I have been weighing options the past few days and had been leaning towards Deoxit Gold, despite the price. That may seal the deal..

I should have narrowed the question originally to either just a pure cleaner like denatured alcohol or whether to use something a cleaner and a lubricant afterwards. Perhaps something like Deoxit F5 which I believe has around 5% lubricant (?)

Oh, and I have no favorite.

Thanks and regards,

11th Sep 2018, 8:49 pm	#1
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Armstrong 526 receiver transistor part Evening, I purchased an Armstrong 526 receiver and had it shipped to the US. It was packaged fair, but not great, and as a result I had a few chipped veneers and other minor exterior case issues which I have sorted. However, upon taking the receiver out of the case I noticed that a copper piece (see image) had come loose and was settled in the tuner section of the receiver, away from anywhere it probably should go. I imagine it rattled off of a transistor? There is another like it in what appears to be the power board. Also, below is another transistor similar in size and appearance to the one with the heatsink? Sleeve. Is this where this belongs? Should I just carefully slip it back over the transistor can? Many thanks for any assistance, Chris Attached Thumbnails

11th Sep 2018, 8:51 pm	#2
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part Image of copper sleeve- Attached Thumbnails

11th Sep 2018, 8:55 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Armstrong 526 receiver transistor part I don't know this receiver or have a schematic. However, that just looks like a clip on heatsink. They do sometimes work loose. What is the transistor type that you think the heatsink fits?

11th Sep 2018, 9:56 pm	#4
roffe Hexode Join Date: Nov 2003 Location: Linkoping, Sweden Posts: 493	Re: Armstrong 526 receiver transistor part Could be from the power amplifier board.There are three heatsinks shaped like this. http://www.audiomisc.co.uk/Armstrong...s/A14board.gif

11th Sep 2018, 11:22 pm	#5
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part I believe you are right in regards to its purpose. It looks to be a slip on heatsink sleeve. I should have posted this earlier, but this link has pertinent diagrams- http://www.audiomisc.co.uk/Armstrong/500/500diags.html The Z.17 power board is the only board I see that has another one of these heat sinks on it, despite the diagrams indicating otherwise. (Maybe I am missing a few?). Neither channel's power amplifier boards have heatsink a over can transistors. I will try rotating the chassis around to see if I can determine what is written on the other can transistors on the Z.17 power board. But without pulling the card itself, I may not be able to see it. The power board contains fuses, rectifier, etc Finally I should add that this version of the receiver looks to have (2) AL100s and (1) AL120 in the power section. Produced late 60s - 1972.

12th Sep 2018, 10:43 am	#6
buggies Heptode Join Date: Jan 2009 Location: West Lothian, UK. Posts: 761	Re: Armstrong 526 receiver transistor part Attached pics show 2 heatsink clips on the power supply board. Would you believe I used the photoshop "add dust" effect? Attached Thumbnails __________________ George

12th Sep 2018, 5:17 pm	#7
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part Thanks George, that cleared it up. It was the suspected transistor. This receiver looks faurly clean inside but I will give it a blow out with duster.. Many thanks all

13th Sep 2018, 4:02 pm	#8
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part I apologize for necroing the thread but I have found one more part that could have come dislodged during shipping. It is the lamp in the white base, in the picture. It is sitting against the back of the tuner section. And the brass colored bar isn't connected to the lamp. Is it possible this is just where it was put by the tech building? All components look original to my eyes. I'd like to correct it before I put this back in the case. Attached Thumbnails

13th Sep 2018, 5:38 pm	#9
buggies Heptode Join Date: Jan 2009 Location: West Lothian, UK. Posts: 761	Re: Armstrong 526 receiver transistor part The lampholder should be slid on to a metal bar at the left hand end of the dial so it illuminates the meter from behind. Attached Thumbnails __________________ George

13th Sep 2018, 9:03 pm	#11
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part Thank you guys, it looks to have come loose during transport. I will put back together and try turning it on tonight after dinner. Grr! I really HOPE there is no electrical damage as a result of the postal service and poorer packing!

14th Sep 2018, 7:55 pm	#12
buggies Heptode Join Date: Jan 2009 Location: West Lothian, UK. Posts: 761	Re: Armstrong 526 receiver transistor part Mine was very reliable over most of its years of use. Only problems were noisy switches and volume control and the plug-in board connectors so all sorted fairly easily. It has not been switched on for a decade or two now so I would be interested to hear if you find any faulty components when you test your unit __________________ George

16th Sep 2018, 4:02 pm	#13
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part I intended to get back to this over the weekend but was prepping for a storm that hasn't lived up to its hype. I hope to return to this over the next few days and will post any discrepancies. Do you have a recommendation for switch/contact cleaner for the older push switches? I have a few pieces off this era's gear and all could do with a cleaning. I have used CRC in the past but would like to get something more appropriate for this older equipment.

16th Sep 2018, 4:45 pm	#14
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Armstrong 526 receiver transistor part I've always used Servisol Super 10 for switxh & potentiometer cleaning in equipment of various makes, models & ages. CPC stock this among a range of cleaning/lubricating products.

16th Sep 2018, 5:10 pm	#15
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Armstrong 526 receiver transistor part Deoxit D5 seems to be the favourite (favorite?) contact cleaner in the US. http://store.caig.com/s.nl/sc.2/category.188/.f It's a bit pricey though, and most contact cleaners should be fine. Don't use (original) WD40, though there is a WD40 branded specialist contact cleaner which should be OK.

16th Sep 2018, 10:57 pm	#16
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Armstrong 526 receiver transistor part Ah! I have been weighing options the past few days and had been leaning towards Deoxit Gold, despite the price. That may seal the deal.. I should have narrowed the question originally to either just a pure cleaner like denatured alcohol or whether to use something a cleaner and a lubricant afterwards. Perhaps something like Deoxit F5 which I believe has around 5% lubricant (?) Oh, and I have no favorite. Thanks and regards,