Bush Arena BH4000 - UK Vintage Radio Repair and Restoration Discussion Forum

cambush · 13th Oct 2021, 4:11 pm

Hi - can anyone here help me to find a schematic for a Bush Arena BH4000? I bought mine as a teenager in the 70s and now I'd like to restore it. I believe (looking at google photos) that perhaps it was also marketed as the Rank Arena T4000. I'm sure I saw - a few years ago - someone advertising the schematic for $20 but can't seem to find it now.

Cobaltblue · 13th Oct 2021, 4:18 pm

Hi and welcome to the forum.

The BH4000 was mentioned in this old thread and samjmann stated he had a copy of the manual, maybe drop him a PM.

https://www.vintage-radio.net/forum/...d.php?t=136287

The Rank T4000 is shown here (with circuits)

https://www.radiomuseum.org/r/rankar...000_t4000.html

Cheers

Mike T

cambush · 13th Oct 2021, 4:46 pm

Thanks Mike. The second link leads to a page where you can request the schematic, but it sends only a truncated version - and the opportunity to pay $25 to get full access - maybe that's what I'd seen before? I'll wait to see if samjmann has anything first! Cheers.

Nuvistor · 13th Oct 2021, 5:43 pm

The radio museum site schematic has three pages, you can download all three in one day. I understand the $25 dollars is to join the site and have unlimited downloads but they only have those 3 pages for this model.
That’s how I understand it.

cambush · 14th Oct 2021, 10:11 am

Thanks Frank - got it! You're right, you have to scroll the thumbnails and request a download for each part - I can print these out and stick them together. Just hope the Rank T4000 is identical to the Bush BH4000 - the pictures certainly look the same.

Big jim · 14th Oct 2021, 11:51 am

Hi I have the full bush arena t4000 4500 service manual if you need any part let me know. Jim

samjmann · 14th Oct 2021, 8:18 pm

Hi cambush.

Like you, I bought my BH-4000 as a teenager back in 1975. It had B&O styling but at a cheaper price!

Have a look in your PM's my message is there. As regards the B-4000 access to the amp is quite difficult and you have to remove various spring clips to get access to the innards. It's a good idea to have as much info as well as the schematic. I think the circuit for the T-4000 is different to that of the BH-4000. The T-4000 and the RTA-2000 all suffered with electrolytic cap failure in the signal path, not just the PSU etc. This was happening back in the seventies! What they're like now is anyones guess!

SJM.

cambush · 16th Oct 2021, 12:43 pm

Hi Big_jim, samjmann is hopefully getting a schematic for me, but if you have a full service manual that would be fantastic!

Big jim · 17th Oct 2021, 10:05 am

Hi which part or parts of the manual do you need! It has 45 pages
Cheers. Jim

cambush · 17th Oct 2021, 10:44 am

Hi Big_jim - is it a user manual or a service manual (with things like test voltages etc?) - I'd be interested in the latter if it talks about the power output stage or the tone control.

Big jim · 17th Oct 2021, 1:39 pm

part 1

Big jim · 17th Oct 2021, 1:46 pm

part 2

Big jim · 17th Oct 2021, 1:51 pm

part 3 if you need anymore let know.

if i was you i would have a bag of 10uf 50v caps and replace ever one you see

jim

cambush · 18th Oct 2021, 9:27 am

Wow - Jim, that's tremendous! Let me see how far I can get and I'll let you know if I need any other pages. Great tip about the caps too... I remember taking it apart in my teens for something and getting in a terrible tangle with the pulleys and string for the tuner indicator. Let's see if an extra 45 years' experience counts for anything!

cambush · 20th Oct 2021, 9:27 pm

Quick update - I dismantled my BH4000 (no easy task) and it's a bit of a horror show. At some point in the distant past it looks like I replaced the power output stage with a couple of integrated power amps (one marked RS 303-236, the other ILP HY60 but otherwise identical). I can only imagine that there was originally some circuit board with the power transistors bolted to the back of the chassis as a heat sink, but no sign of them. What was I thinking? Can anyone confirm if indeed such a circuit board should be there (in the big gap in the photo)? ******************************mgtWoZ7h9vmHP3PR8

Also, any tips on how to remove the filter circuit board - the one with the sliders? Seems immovable...

Big jim · 21st Oct 2021, 12:11 pm

Yes there should be 2 power amp pcb's I've also noticed I haven't uploaded them pictures and circuits! If I have time I will in the morning or definitely the weekend. Jim

cambush · 21st Oct 2021, 5:37 pm

I'm gutted - can't believe I would have been so stupid to have just thrown away the old ones - think I'll have to go routing through all my old boxes in the garage! I suppose as a last resort I could fabricate replacement PCBs using your service manual photos as a starting point.

Big jim · 24th Oct 2021, 9:09 am

T4000

Big jim · 24th Oct 2021, 9:14 am

t4000

samjmann · 24th Oct 2021, 9:18 pm

Apologies cambush for not sending the scans. Big Jim came to the rescue I see! Been stupidly this week, slipped my mind.
Such a shame the amp pcb's are missing. Hope your garage search is successful. SJM.

13th Oct 2021, 4:11 pm	#1
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Bush Arena BH4000 Hi - can anyone here help me to find a schematic for a Bush Arena BH4000? I bought mine as a teenager in the 70s and now I'd like to restore it. I believe (looking at google photos) that perhaps it was also marketed as the Rank Arena T4000. I'm sure I saw - a few years ago - someone advertising the schematic for $20 but can't seem to find it now.

13th Oct 2021, 4:18 pm	#2
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,859	Re: Bush Arena BH4000 Hi and welcome to the forum. The BH4000 was mentioned in this old thread and samjmann stated he had a copy of the manual, maybe drop him a PM. https://www.vintage-radio.net/forum/...d.php?t=136287 The Rank T4000 is shown here (with circuits) https://www.radiomuseum.org/r/rankar...000_t4000.html Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk Last edited by Cobaltblue; 13th Oct 2021 at 4:18 pm. Reason: forgot link

13th Oct 2021, 4:46 pm	#3
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 Thanks Mike. The second link leads to a page where you can request the schematic, but it sends only a truncated version - and the opportunity to pay $25 to get full access - maybe that's what I'd seen before? I'll wait to see if samjmann has anything first! Cheers.

13th Oct 2021, 5:43 pm	#4
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,431	Re: Bush Arena BH4000 The radio museum site schematic has three pages, you can download all three in one day. I understand the $25 dollars is to join the site and have unlimited downloads but they only have those 3 pages for this model. That’s how I understand it. __________________ Frank

14th Oct 2021, 10:11 am	#5
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 Thanks Frank - got it! You're right, you have to scroll the thumbnails and request a download for each part - I can print these out and stick them together. Just hope the Rank T4000 is identical to the Bush BH4000 - the pictures certainly look the same.

14th Oct 2021, 11:51 am	#6
Big jim Tetrode Join Date: Sep 2006 Location: South London, UK. Posts: 86	Re: Bush Arena BH4000 Hi I have the full bush arena t4000 4500 service manual if you need any part let me know. Jim

14th Oct 2021, 8:18 pm	#7
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 648	Re: Bush Arena BH4000 Hi cambush. Like you, I bought my BH-4000 as a teenager back in 1975. It had B&O styling but at a cheaper price! Have a look in your PM's my message is there. As regards the B-4000 access to the amp is quite difficult and you have to remove various spring clips to get access to the innards. It's a good idea to have as much info as well as the schematic. I think the circuit for the T-4000 is different to that of the BH-4000. The T-4000 and the RTA-2000 all suffered with electrolytic cap failure in the signal path, not just the PSU etc. This was happening back in the seventies! What they're like now is anyones guess! SJM. __________________ It's never been right since we've had it... Last edited by samjmann; 14th Oct 2021 at 8:24 pm. Reason: Missing sentence.

16th Oct 2021, 12:43 pm	#8
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 Hi Big_jim, samjmann is hopefully getting a schematic for me, but if you have a full service manual that would be fantastic!

17th Oct 2021, 10:05 am	#9
Big jim Tetrode Join Date: Sep 2006 Location: South London, UK. Posts: 86	Re: Bush Arena BH4000 Hi which part or parts of the manual do you need! It has 45 pages Cheers. Jim

17th Oct 2021, 10:44 am	#10
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 Hi Big_jim - is it a user manual or a service manual (with things like test voltages etc?) - I'd be interested in the latter if it talks about the power output stage or the tone control.

18th Oct 2021, 9:27 am	#14
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 Wow - Jim, that's tremendous! Let me see how far I can get and I'll let you know if I need any other pages. Great tip about the caps too... I remember taking it apart in my teens for something and getting in a terrible tangle with the pulleys and string for the tuner indicator. Let's see if an extra 45 years' experience counts for anything!

20th Oct 2021, 9:27 pm	#15
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 Quick update - I dismantled my BH4000 (no easy task) and it's a bit of a horror show. At some point in the distant past it looks like I replaced the power output stage with a couple of integrated power amps (one marked RS 303-236, the other ILP HY60 but otherwise identical). I can only imagine that there was originally some circuit board with the power transistors bolted to the back of the chassis as a heat sink, but no sign of them. What was I thinking? Can anyone confirm if indeed such a circuit board should be there (in the big gap in the photo)? ******************************mgtWoZ7h9vmHP3PR8 Also, any tips on how to remove the filter circuit board - the one with the sliders? Seems immovable...

21st Oct 2021, 12:11 pm	#16
Big jim Tetrode Join Date: Sep 2006 Location: South London, UK. Posts: 86	Re: Bush Arena BH4000 Yes there should be 2 power amp pcb's I've also noticed I haven't uploaded them pictures and circuits! If I have time I will in the morning or definitely the weekend. Jim

21st Oct 2021, 5:37 pm	#17
cambush Triode Join Date: Oct 2021 Location: Cambridge, Cambridgeshire, UK. Posts: 20	Re: Bush Arena BH4000 I'm gutted - can't believe I would have been so stupid to have just thrown away the old ones - think I'll have to go routing through all my old boxes in the garage! I suppose as a last resort I could fabricate replacement PCBs using your service manual photos as a starting point.

24th Oct 2021, 9:18 pm	#20
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 648	Re: Bush Arena BH4000 Apologies cambush for not sending the scans. Big Jim came to the rescue I see! Been stupidly this week, slipped my mind. Such a shame the amp pcb's are missing. Hope your garage search is successful. SJM. __________________ It's never been right since we've had it...