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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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23rd Jun 2008, 11:48 am | #1 |
Heptode
Join Date: Jun 2003
Location: Bristol, UK.
Posts: 900
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McMichael "Batman"
This is the first time I have posted here - not because it's the first radio I have restored, but it's the first time I have had the time to write about it (since semi-retirement)
I bought this from a forum member (Rob - MB60) several years ago and it went into my 'to do' pile - which I have only just started on! I bought it because I'm stupid about valve portables and I really liked the look of this one (see pics). It's really well made and well laid out - easy to get out of the box and easy to service. It uses 90v + 7.5v batteries or a dropper + selenium rectifier for mains. I thought I would try my 90v adapter with a 7.5v input from a large Farnell VR1 PSU (bought from a swapmeet) - connected it all up and ... nothing! So I took it out of the box and realised that V4 (DL94) was missing! My only excuse is that it is an upside down chassis and it is difficult to spot the missing valve (at the back of the chassis). Anyway - put in a replacement from my small stock, connected up the aerial (integrated into the back cover) and the speaker - switched on again and - success - a few faint stations were heard! Next objective: get it working from the mains. I use a series lamp limiter most of the time - as it's permanently set up on my bench (and I'm too lazy to get the variac out!) - plugged it in through this, switched on and - predictably, nothing. Check voltages - nothing coming out of the rectifier (unsurprisingly) - I couldn't remember which 1N4*** series diode to replace it with, so I asked here: https://www.vintage-radio.net/forum/...ad.php?t=28757 I tried a 1N4007 plus a 100ohm wire wound . The radio was now working on mains, but was very distorted. I changed THAT capacitor and wow! what a difference! Volume was suspiciously loud, so I had a look at the filaments in the dark - dull red glow - OOPS! switched off and upped the 100ohm WW to a 250ohms and it seemed to produce the right voltages across the filaments (I learned a long time ago that these are far more important in a valve portable than HT voltage). Apparently a better method is to use a 1k wirewound pot, but I didn't have one of these to hand - (please see the thread above for the methodology) changed all the wax caps - most were out of tolerance, mounted the RS 250ohm WW where the rectifier had been (very neat!) and switched on - and - nothing! Checked caps, my soldering, couldn't work it out! So I did what every sensible person does - walked away from it for a couple of weeks (nb: I'm not saying that people who had to do this for a living aren't sensible - you can draw your own conclusions here...) Came back to it last night and noticed that I must have turned the voltage dropper so that a contact was close to shorting out on the smoothing cap - at first, I just turned it back and tightened it up - there were no spark marks / burn marks where they had been touching, so I assumed it wasn't that - however, I tried it again and - success! Checked the voltages, checked the chassis - the tuning action was very stiff - it's an unusual design - the spindle has a 'fine tune' action for about 3/4 of a turn - this was ok, but after that, it became very 'heavy', there was some black gunge at the bottom of the spindle, so I used some WD40 to clean it off - a little light grease to lubricate it and it seems ok now. Replaced the (short) mains cable, put it all back together tweaked the aerial trimmers for maximum output - and it is working really well. I have decided not to try to clean the cabinet at all - in my experience, damage/ discolouration is done to the covering material by cleaning. The covering material on this radio doesn't appear to be rexine - neither is it particularly dirty, so I will just leave it alone for now - and just enjoy the radio! |
23rd Jun 2008, 12:15 pm | #2 |
Nonode
Join Date: Jun 2005
Location: Western Lake District, Cumbria (CA20) - UK
Posts: 2,136
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Re: McMichael "Batman"
What a nice little set!
It is fairly unusual and I've always liked the sets with flaps over the controls (I have a similar Pilot one in storage somewhere). From the pictures the case doesn't seem to be too badly marked so the minimum of restoration is a good idea. Interesting to see the McMichael logo on the handle too. A nice job all round. Regards,
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Brian |
23rd Jun 2008, 1:27 pm | #3 |
Dekatron
Join Date: Jan 2003
Location: Bradford on Avon, Wiltshire, UK.
Posts: 3,310
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Re: McMichael "Batman"
Hi all.
I used to have one of these( already modified with a BY127 in leu of the selenium rectifier-not sure if there was a resistor as I never took the chassis out) when I was a lad. Quite surprised to see a flap, mine never had one! Mine had been covered in blue rexine type stuff by some previous owner. It ran for many years before it fell silent, but I can't remember what happened to it. ISTR it sounded good though, as it has a reasonable size wooden case. Good resto.
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"Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly." |
24th Jun 2008, 9:30 am | #4 |
Retired Dormant Member
Join Date: Jul 2007
Location: Christchurch New Zealand
Posts: 96
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Re: McMichael "Batman"
Very cool radio! I'm a sucker for portables too although I concentrate on transistors. However there are some great looking valve portables out there! I always find it amusing if you put the question to lay people regarding when the first portable radio was manufactured; many don't realise there that portables have been around in one form or another for 85 years or so. So what year is the 'Batman' and why is it nicknamed so?
-james- |
24th Jun 2008, 6:26 pm | #5 | |
Heptode
Join Date: Jun 2003
Location: Bristol, UK.
Posts: 900
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Re: McMichael "Batman"
Quote:
not sure of the year - nearest I can come is 1946-1953 - I would guess at early fifties, as it uses the '91 series, apart from the DL94 output valve. As for the Batman name, it was marketed with that name (a 'Batman' was an officers' valet) - the actual model number was 352 Cheers Andy |
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25th Jun 2008, 5:22 am | #6 |
Retired Dormant Member
Join Date: Jul 2007
Location: Christchurch New Zealand
Posts: 96
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Re: McMichael "Batman"
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26th Jun 2008, 10:17 am | #7 |
Nonode
Join Date: May 2005
Location: Godalming, Surrey, UK.
Posts: 2,593
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Re: McMichael "Batman"
Well done Andy
That's quite a nice mains/battery portable set. A similar rexine cover also appears on the Bush BAC31 and some of the examples I've seen look a bit washed out so as you say it might be better not to attempt to scrub it clean. A quick wipe and maybe repolish/revarnish the brass fittings would suffice. Howard |
27th Jun 2008, 4:59 pm | #8 |
Octode
Join Date: Dec 2005
Location: Near Stowmarket, Suffolk, UK.
Posts: 1,962
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Re: McMichael "Batman"
Brilliant restoration! I've seen a few Batmans sell but all for more than I can afford . It's on the list of McMichaels to get though .
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