ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Well, should you decide to give up on the etching, don’t worry, you will think about it for a while, then you’ll just forget about it.
All you will behold is those fantastic Frede fascias and those superb sliders from Martin, not to mention the sound, which still amazes me to this day.
Why did you go for satin instead of matte?
Jacques
No particular reason.....I have both available, just liked the look of the satin finish more really, and I have already painted the side panels in satin ;¬)
Craig
new feet...……...
And replaced all the trimmers...the 20vdc one was very flakey, and all of them where devils to remove. The bourne replacements for the tuning meter and muting where not an exact fit...had to band the wiper leg forward and down to bet a fit, made a start on the caps too.
Ok first shot....I know the colour is all wrong, but it gave the best contrast.....never be as good as the original but its the best I can come up with.
Much better option than leaving the back black (as I type this I feel the need to play some Amy Winehouse song haha). Nice Craig!
Craig:Ok first shot....I know the colour is all wrong, but it gave the best contrast.....never be as good as the original but its the best I can come up with.
I know i am a PIB, but i cant say that I like it, maybe silk screen printing, will cost an arm and a leg, I know I know
Collecting Vintage B&O is not a hobby, its a lifestyle.
Hi,
just remembered the ancient times, around 1988 / 89 when MINOLTA had white toner for some copiers in their portfolio. This was used for some special customer who wanted white on colored paper. What was black on the original was copied with white toner, So using black paper gave a 'negative' copy.
It was really white toner powder instead of the usual black one and it gave very good results. So it is possible to use white toner The problem is just to find someone who still owns such a copier I think those machines were 'EP270' and 'EP370 (Z)' where the developping unit was exchanged with a 'white' one. There were several colors available: Black, white, red blue and green as fas as i remember ( i'm getting older )
Sometime in the last 30 years Minolta sold the copier / printer business to Konica and are now known as Konica Minolta
Maybe a small copy shop, advertising agency, ... still has one of those machines available.
Ralph-Marcus
Here it is....love it or hate it, still looks a lot better than it did a month ago ;¬)
Re build underway.....still got a couple of capacitors to replace but things are moving on ;¬)
soldiering on....caps and trimmers all changed out
Cabinet re assembly next up....
Before I box this up I thought it wise to put some power on and see what happens...….fitted the new lamps from Martin and with the variac powered up slowly, nothing got hot, measured the 20vdc power rail and adjusted it down from 22vdc back to 20vdc....plugged in a Ariel lead with a plug also from Martin and with a Beomaster 4400 connected up commenced to adjust the tuner....got a good selection of stations with very clear reception and a very pleasing quality....however the stereo lamp is on constantly, something is amis….I will remove and test the associated transistors tomorrow and see if I can find anything, any advice will be well received as always ;¬)
Took a closer look at AC187 this evening.....
Found to be a short across the emitter and the collector......that'll make the lamp shine all day long!.....so to start with I'm looking for an equivalent for this little devil, I love this transistor tester...…..
Still awaiting delivery of the shorted transistor....but carried on assembling what I can in the meanwhile, I think she's coming on fine
With what did you change the AC187
Soren
I have ordered a AC187 as a replacement, still waiting to take delivery....was due yesterday. It's quite a high current NPN and I'm not sure what would be an acceptable later equivalent.
This little fellow turned up in the post today....identify his connections and get him in, see what else in lying in wait!
This is not going well.....on initial replacement the set came to life, sounded fine and an adjustment of the tuning slide gave good deflections of the tuning meter and the stereo lamp came on an off with the adjustments. However the signal seemed to fade after a few minutes....the tuning meter deflection fell away and the stereo lamp stopped lighting up, also the stations I was tuning too lost there clear amplification, after lots of searching around I found I had managed to install the AC187 collector and emitter the wrong way around.....schoolboy error put it back correctly....still got the poor meter deflection, no stereo lamp and poor reception.....furthermore the full set up procedure as described in the manual, and very likely what I'm going to need to do, looks very daunting.....I wondered if the few caps I have replaced with polyester non polorised components may be responsible....also when I pulled the AC187 and checked it again its Hfe is down to 18...…..
Such fun
Craig, this happens to all of us.
Have a good break on this project, do something else, and then go back to it. It will have a happy ending I’m sure.
The Wima caps can’t possibly do that, no.
Craig,
Reversing the transistor might have broken something else. If the rest of tuner was working fine just before changing it then you can strongly believe that is the case. Now which one?...
Regarding the replacement components, I always treated tuners differently than amplifiers.
- Tantals and polypropylenes are precision capacitors often of 5-10% tolerance and if they are outside the signal path, I use the same type and precision as before. They also leak less compared to polyester boxed film and boxed films are often of higher tolerance (~20%).
Unless you have the equipment to align your tuner, avoid drastic changes as much as you can.
Jean
Yes I agree...something has suffered as a result of my mistake.....I will try and track it down, I do have a signal generator with a sweep function and I have on order a more respectable scope...the one I currently use is struggling (£20 on ebay a few years ago) so I will at the very least have a look at whats going on...the only coil I have disturbed is 149...I thinks its only job is to energise the stereo lamp......however I have no way of knowing if anyone else has been inside and had a go.....as the set does pick up a good strong signal in the first instance is encouraging...just need to find out why it fades out after a few minutes...
Looking at the alignment and adjustment chart I can see all the frequency signals I need to inject, but at what voltage level? my sig gen will go down to 1.0v p/p is this low enough to inject into the Ariel socket, seems a bit high to me? Anyone got any tips or advice....apart from don't touch anything!
You have an RF Stereo signal generator? Your alignment data aren't in the service manual?
I'm looking to buy one for years but never moved on since i don't need it that much
looks like that may be a problem then.....the manual states inputs in Mc/s....which I understand convert to Mhz, my signal generator only goes up to 2Mhz...so looks like I have fallen at the first fence ;¬)
Just powered her up again with AC187 disconnected and the reception is back to being good again!......I have a feeling my problem is the makeshift aerial im using....it only has one wire, looking on the information superhighway for a FM aerial I should be using two wires.....going to the pub!
The BBC you say......didn't know that, I wonder if they have any left is a dusty store room somewhere? Ok....hastily put this dipole antenna together today, and on connecting up the reception I was getting was vastly improved.....
However as I have AC187 out of circuit the stereo lamp remains un lit...….and after around 2 to 3 mins The excellent reception had deteriorated to noise again. I'm thinking that as I do get good reception to start with that the tuner may well be aligned OK.....and I'm leaning towards a noisy transistor, unless anyone can advise otherwise I'm going to take the view that all is good with the coils settings and not fiddle with anything along those lines. I will see if I can tune into a strong station before I get the noise and leave the set tuned to that frequency and follow it through to see if I can find out where is gets lost.
Craig:The BBC you say......didn't know that, I wonder if they have any left is a dusty store room somewhere?
I had a tricky reception problem on a Beomaster 3000-2 tuner that Nick aka Solderon helped me with. It was permanent rather than intermittent and turned out to be a duff styroflex cap on one of the IF coil tuning circuits.
These caps have a pretty poor rep and it just might be worth checking them in case one of yours is borderline.
Simon
When you are losing the signal, are the voltages still OK across the circuit?
Sounds like a leaking transistors, faulty capacitor or maybe a resistor under load...
Let me check you pictures again...
Those black bullet transistors are known to be noisy....
Charles
Thanks for that....I'm currently confirming the power supply levels around the board....so far I have confirmed the 20vdc supply, the 12vdc to th front end is ok at around 10.5vdc. I'm working through the IF stage supplies.....
I have identified a missing Bias on the first stage of the stereo decoder as shown below.....this will be my next task, I'm taking advice from solderon regarding this as I'm in the dark with tuners....I will continue to chronicle the exercise as iI go on....
Made some measurements as attached...something is amiss around the muting, stereo level circuit, Also when taking these measurements I had the set tuned to a station in the lower MHz area (around 93)....cant pick up much of anything higher up, the reception was still poor but stable, as I connected the multimeter probe to the collector of BC113 (1) position 3 the hissing disappeared! checked around a few more places on the 20v rail and got the same result.....suspecting a grounding issue I realised I was still powering the set via my variac, disconnected it and powered direct from the mains and the hiss is now gone....a small step but still an improvement. Also when I depress the muting button on the front of the set I loose all output to the amp?
If I where you, I would replace those BC113 with BC550B.
Would BC549BTA be an acceptable replacement.....it looks quite close to me?
Following receipt of the AC187 and the replacement of the 1.6uf cap (111) and the reflowing of all the solder joints I've made, not too many actually, I now have a very respectable reception....due in part I'm thinking to fiddling around with the dipole antenna, so convinced am I that the antenna is the villain I have ordered a "all singing all dancing" FM antenna from amazon.....I'm also dipping in and out of stereo reception. This is to be expected now I have ordered replacement transistors! I'm not convinced I'm completely out of the woods.....Peter is calling round on Saturday to collect his Beolab 5000 and has kindly offered to loan me his Beomaster 5000 to enable me to make some comparison measurements. None the less I'm in a better place....and thanks to Solderon's encouragement I'm feeling good about the exercise once again.....