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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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21st Jun 2017, 9:17 pm | #1 |
Pentode
Join Date: May 2015
Location: Cork, Munster, Ireland
Posts: 114
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Bush RP21.
Hello.
I just spotted a redundant Bush rRP21 but looks cosmetically well (red and white) the seller wants €80 for it. I would like to know if this model is valuable and if it's worth €80, also are these models difficult and expensive to restore? All advice will be welcomed. |
21st Jun 2017, 10:07 pm | #2 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
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Re: Bush RP21.
A 1950's EAR record player for sale on the web that claims to be restored is about £90. The seller lists what has been done to the RP and it seems comprehensive so 80 Euros for an unknown seems high to me, but of course it's worth whatever someone will pay.
The makers service manual is available from the link at the top of the page if you want to know what's inside the RP. Frank |
21st Jun 2017, 11:28 pm | #3 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
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Re: Bush RP21.
It's got a two stage amp with NFB and an isolated psu so it's off to a reasonable start and could handle the "Chinese Cheapy" ceramic cartridge if necessary (and if it can be fitted, which might be a challenge). Unless a transformer or two is duff (unlikely) any electrical problems should be fixable relatively cheaply.
It has an electrostatic tweeter which will probably be dead. Depending on its condition it sounds pricey but not outrageously so.
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22nd Jun 2017, 3:08 pm | #4 |
Retired Dormant Member
Join Date: Jul 2005
Location: Somerset, UK.
Posts: 334
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Re: Bush RP21.
By co-incidence, this is the player to which the Garrard RC121/4H I recently did a thread about restoring. I fitted a generic "red" cartridge to it, which is straightforward as long as the cartridge has its bracket with it and this drives the two stage amp quite well and gives a good sound.
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22nd Jun 2017, 8:04 pm | #5 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,763
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Re: Bush RP21.
As things go, if the player is in good cosmetic condition, €80.00 seems about the going rate and a fair price from both parties point of view.
As to 'would it be difficult or expensive to restore', I can't advise as to the record deck aspect - cartridges etc, but certainly on the electronics side, provided that the mains transformer and output transformer are intact, it would be neither expensive nor difficult to restore. Despite advice to the contrary with old equipment untll it's been checked out, no doubt the seller will have turned it on and maybe played a record on it. If so, that does at least exonerate the motor, output transformer, mains transformer, valves, speaker and on/off switch! Looking at the circuit, the component count is low, as is usually the case with valved record players. There are 4 paper tubular capacitors, two metalised paper capacitors, plus two silver ceramic ones. If you bought the player and were minded to do any restoration work on it, the very least that you should do is to replace the .01uF audio coupling capacitor (C2 on the maker's service data), but with so few caps, it would neither be expensive nor difficult to replace all of the paper ones. The reservoir and smoothing capacitors - each 32uF - are in a twin can. They might reform fine, but if there is any 50Hz hum, the twin can will most likely need replacement. A replacement will be easy to source, and probably cost little more than €15.00. There are ten fixed resistors, some of which will most likely have drifter high in value, but even when new, six were +/- 20% tolerance and the other four were +/- 10%, so unless they've drifted way higher than that, wouldn't cause a problem if left in place. The amplifier uses three valves - an EBC81 double diode triode, with just the triode section used, followed by an EL84 output valve. For rectification, it uses an EZ80 full wave rectifier valve, but with the two anodes strapped together as a half-wave rectifier. It uses a double-wound mains transformer and the chassis is earthed, so it's inherently safer than simpler designs which don't use a double-wound transformer. (The motor is directly across the mains, in serves with the motor control switch to switch of the motor at the end of a record having played). One possible complication is that the tone control has an anti-log track and is combined with the double pole mains switch, so if the switch is defective - open circuit for example - it will be next to impossible to find a replacement without someone such as Blore Edwards making one to order. That said, a linear track pot would probably be satisfactory should it come to that. The un-switched volume control has a 1 Meg log track, so no complications there. If you download the maker's service data from the top RH of this page, you'll see that the chassis layout isn't cramped, so would be easy to work on. Hope these observations are of help if you decide to buy it.
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David. BVWS Member. G-QRP Club member 1339. |
22nd Jun 2017, 8:20 pm | #6 | |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
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Re: Bush RP21.
Quote:
http://www.vintage-radio.net/forum/s...0&postcount=36
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
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23rd Jun 2017, 2:31 pm | #7 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
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Re: Bush RP21.
Fit a log track pot, reverse the outer connections, and live with the tone control operating "backwards"?
If it came on "bright" and you advanced to get "woolly", the other way round would be no big deal, nor vice versa.
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....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
23rd Jun 2017, 9:50 pm | #8 |
Pentode
Join Date: May 2015
Location: Cork, Munster, Ireland
Posts: 114
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Re: Bush RP21.
Thanks to all of you who advised me on this, regrettably i'm not well up on the electrical side of thing but i know a man here in Ireland does a complete service for vintage electronics, he is qualified so i would trust him to fix any problems so i might venture a gamble with it.
many thanks again |