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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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13th Sep 2006, 5:12 pm | #21 |
Diode
Join Date: Aug 2006
Location: Alvaston, Derby, Derbyshire.
Posts: 4
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Re: Roberts R707 - any good ?
Totally agree on the sound quality. Of all the Roberts I've repaired, this one will take some beating. Decided some time ago that this was one to keep hold of. Thankfully, the volume control responded well to cleaning - good job really, with the ganging of different value pots! Batteries available at our local market. B & Q also sell them, as do Halfords (along with PP9's). Slightly over-priced. I always take a meter along to test before I buy. On a couple of occasions the PP9's have read less than 1.5v!
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18th Sep 2006, 6:53 pm | #22 |
Nonode
Join Date: May 2005
Location: Godalming, Surrey, UK.
Posts: 2,593
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Re: Roberts R707 - any good ?
Hello,
The early 1969 Roberts R707 mentionned above has arrived and its in super cosmetic condition, working OK on FM, but it doesn't work on AM I gave the lid on the Mullard LP1164 module a hard tap with a screwdriver handle and it came back to life briefly so methinks the problem lies in there. Surely this late 1960s/1970s set doesn't have AF117s in it, does it Are these modules easy to get at inside and are they repairable ? There was a thread about repairing these modules but it has been deleted now. I assume these modules are no longer available .... If I can get in there, in will go AF124s/AF125s Howard |
18th Sep 2006, 10:53 pm | #23 | |
Nonode
Join Date: Jun 2005
Location: Western Lake District, Cumbria (CA20) - UK
Posts: 2,136
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Re: Roberts R707 - any good ?
Quote:
Hi Howard, I have some modules in a job lot of stuff I got hold of a little while ago. I wouldn't like to say what state they are in and I dont remember which they are so I'll need to retrieve them from the loft when I get a chance. I've toyed with the idea of making a rig to repair these - shouldn't be too tricky given the amount of test gear I have lying around. The problem is that I don't have a workshop at the moment so it's a long term project for when the extension is finished sometime in the new year. I'll report back when I've had a stock check. Regards,
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Brian |
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19th Sep 2006, 6:56 pm | #24 |
Nonode
Join Date: May 2005
Location: Godalming, Surrey, UK.
Posts: 2,593
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Re: Roberts R707 - any good ?
Hello Brian,
That is very kind of you. What I'd probably do is take it apart, check to see if repair is feasible and if so then replace the AF117s with AF127s and then use the module to replace the one in my set. I look forward to hearing from you again after you've ventured into your loft ! You could probably then have the old one back, repaired of course ! Howard |
19th Sep 2006, 9:38 pm | #25 |
Nonode
Join Date: Jun 2005
Location: Western Lake District, Cumbria (CA20) - UK
Posts: 2,136
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Re: Roberts R707 - any good ?
Hi Howard,
I'll be in the loft at the weekend I suspect. I have had the Mullard / Roberts modules apart and repaired them before - a long time ago it must be admitted. The most difficult bit is to pluck up the courage to start! I need to have a good clear out of the loft and house before the builders arrive - and we have visitors in a couple of weeks so most of the 30 sets in the spare room have to be moved, and the amplifier, Ferrograph, test gear...................... I'm trying to rent a lock up store in the meantime. I'll be in touch soon. Regards,
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Brian |
8th Nov 2006, 6:11 pm | #26 |
Pentode
Join Date: Jun 2006
Location: Crawley Down, West Sussex, UK.
Posts: 151
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Re: Roberts R707 - any good ?
Wow the 707 is great isn't it! Sounds better than the Hackers I think. Deep bass and sharp treble. A great radio all in all.
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My Youtube channel https://www.youtube.com/user/simonspiers |
8th Nov 2006, 11:49 pm | #27 | |
Heptode
Join Date: May 2004
Location: Ellington, Northumberland, UK.
Posts: 815
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Re: Roberts R707 - any good ?
Quote:
I'm sitting listening to the wonderful, late and completely barking Alex Harvey's "Action Strasse" as being played by Mark Radcliffe on BBC R2, on this R707 as I sit here. I am very much a lover of most things Hacker, but the 707 is simply more involving to listen to than even the best Hackers (RP37 and RP75) here! There, I said it! The amazing thing about this set is that the speaker in 707s is the same one as fitted to R600s, R606s and early 606MBs yet the audio amp in the beast is just so much better than anything else from Roberts at the time of the 707 or since. I still have another 707 chassis on the "to do" heap, and would really like to build that into some kind of floor-standing cabinet with a BIG speaker mounted on a proper baffle. Hmm, must stop this thinking lark, it does me no good.
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John. |
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9th Nov 2006, 10:14 am | #28 | |
Nonode
Join Date: May 2005
Location: Godalming, Surrey, UK.
Posts: 2,593
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Re: Roberts R707 - any good ?
Quote:
Howard. |
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9th Nov 2006, 12:28 pm | #29 |
Heptode
Join Date: May 2004
Location: Ellington, Northumberland, UK.
Posts: 815
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Re: Roberts R707 - any good ?
I stand corrected.
That said, some of these things have their speaker located on all four captive screws, some have the bottom two holes in the basket above the screws with little clamps on the screws spanning the gap between. I'll have a look later on, but I suspect that it's something to do with the changeover from the cadmium-plated to the black painted basket as well. I'm listening to my good one again now, well worth the skinned fingers and the iron burns!
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John. |
9th Nov 2006, 5:39 pm | #30 |
Heptode
Join Date: Jul 2006
Location: North Herts. UK.
Posts: 549
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Re: Roberts R707 - any good ?
I have been wondering if the speaker is a particular weak spot on the R707, though this is based on the slim and not-very-scientific evidence that neither of mine has an original one.
The £5 car boot sale 707 has a smaller R600/606 type, fixed onto two diametrically opposed mounting screws. A bit of an 'orrible bodge, but it sounds fine. The £6 one from Another Place has an old ELAC speaker fitted. It's the correct size for the mounting screws, but the magnet is so big that it fouls the battery carrier. When I first got it, somebody had managed to shoehorn everything in, but I'm currently running it on a PSU, without the battery carrier in place, just to reduce the strain on the cabinet. Tom |
13th Oct 2007, 8:21 pm | #31 |
Retired Dormant Member
Join Date: Oct 2007
Location: Chester
Posts: 2
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Re: Roberts R707 - any good ?
I got a roberts r707 from a jumble sale today for 10p! excellent condition. Does anyone know the correct voltage to put through it using a mains adapter. I'm currently using it at 9v.
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14th Oct 2007, 9:25 am | #32 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
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Re: Roberts R707 - any good ?
Hi FH and welcome.
The R707 uses 2 x 996 6 volt batteries, so your answer is 12 volts. 996s are still freely available. 9v will work, sort of. How are you connecting the adapter? AFAIK there isn't a socket on these. You really need to start a new thread for this, if you are doing any more to the Roberts, as any posts on this old thread from 2006 might get unread. 10p is a good price!!
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Mike. |
14th Oct 2007, 10:29 am | #33 |
Heptode
Join Date: May 2004
Location: Ellington, Northumberland, UK.
Posts: 815
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Re: Roberts R707 - any good ?
Mike, FH, only the later 707s have a DC-in socket, 12V centre positive, so you're both right.
10p! you are a very lucky man, whether or not it can be coaxed into life, its parts could be sold as spares on the forum or elsewhere for far more. Not that parting the thing out would be an option once you have heard it perform. Since I posted earlier in this thread regarding the original question about whether the things are any good, I have been the owner of the other good quality portable with the name/number "707", the slim Beolit and that is really the only radio in this house (there are quite a few) that gives a more involving sound than the Roberts, but even the B&O is more fussy about where it is placed. I love my R707(s) and as has been said many times before, they just soldier on for ages on a pair of batteries, so much so that the everyday one has been on the same pair for over a year now and shows no signs of needing more just yet!
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John. |
14th Oct 2007, 4:31 pm | #34 |
Retired Dormant Member
Join Date: Oct 2007
Location: Chester
Posts: 2
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Re: Roberts R707 - any good ?
no. i have already heard it!
love the sound. awesome set. |
15th Oct 2007, 7:55 am | #35 | |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
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Re: Roberts R707 - any good ?
Quote:
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Mike. |
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15th Oct 2007, 7:51 pm | #36 |
Retired Dormant Member
Join Date: Dec 2002
Location: County Down, Northern Ireland, UK.
Posts: 275
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Re: Roberts R707 - any good ?
I am tempted to try and get hold of one. Which of the modules contain the dreaded AF transistors, the FM tuner LP1179 or the LP1164 IF amplifier or both? How difficult are they to remove and repair?
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16th Oct 2007, 11:29 am | #37 |
Heptode
Join Date: May 2004
Location: Ellington, Northumberland, UK.
Posts: 815
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Re: Roberts R707 - any good ?
This would depend upon the age of the set. Later ones, after the DC input was added have, so far from the ones I've seen, been all-silicon. I think these are from about 1973 onwards, but I'm sure someone will be along to confirm the exact date.
I've not met a problem with the FM tuner on one of these that couldn't be addressed with a few caps, but then I've only done about half a dozen of the things since I started to play with them! I have one that I know to be original, from 1971, and it has AF12*s in the i/f amp, all of which were fine, but only after I'd removed the module did I find the poor soldering that actually caused the problems on that example. The modules aren't "difficult" to remove as such, but the 1164 is very fiddly since, if you want to do the job "by the book", there are a lot of connections including the bandchange assembly that have to come off. Unofficially, and if you want to repair a set to enjoy for your own use, going into the cover of the module with a very fine Dremel disc around three sides, snipping out the faulty parts, then fitting replacements with longer leadouts from above with a very fine iron does the trick, stick the lid of the module down afterwards with some epoxy resin. Doing it this way, only the screw that holds the clips to the heatsink on the output transistors to the right (As you look at it from the back of the chassis) of the module need be removed, and then it doesn't have to come right the way out. The 1179 is much easier to remove, but then far less likely to need attention. But that obviously wouldn't be a suitable technique if you want elegance!
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John. |
16th Oct 2007, 1:23 pm | #38 |
Heptode
Join Date: Jul 2006
Location: North Herts. UK.
Posts: 549
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Re: Roberts R707 - any good ?
At least two different tuner modules were fitted to the R707. The later of my two (with DC input socket) has the LP1179/2, but the earlier one has a module labelled LP1402/2. Presumably that's the one with the AF11*s. The IF modules are LP1164/1 in both cases.
Tom |