I see someone already claims to have done so. Welcome to the Internet, where you can find just about anything.
In addition to making sure you have the right line voltage available for it, before powering it up I'd "reform" the main filter electrolytic capactitor(s). You can do this with a vintage "capacitor bridge/checker" as once made by Heathkit, Eico and others. I have an Eico 950 (with a round Magic Eye tube) that has a feature to test capacitors for leakage at rated voltage. It's also useful for reforming caps.
I see two transformers, one power, the other for the speaker, so it looks like it's not a "hot chassis" design. That's absolutely neccesary when it's got an external input like for phono.
There's a four-pin connector on the right, looks like for a loop antenna that might be wound onto the back cover, which also might plug in when you put the back cover on like the power cord does.
I googled EM84, it's an unusual model of "Magic Eye" tube, used for signal level and/or tuning indication. All the ones I've seen have a round indicator at the end/top of the tube showing a varying angle with the input voltage (thus the original name magic eye). I've heard of this "linear" type but don't recall actually seeing one in person:
EM84/6FG6, PM84/4FG6 and UM84/12FG6
Hi Bigun,
I may possibly have a diagram for it. I'm not sure, but I have some collections that may include it. The offer that davorin made to you is something you should look into. I trust that what is odd for us is very normal for him in the way of service information. Just like "the all American five" sets are to us over here.
It does have a power transformer that should isolate the chassis from the AC mains, but there may also be a small capacitor that has shorted that can make the chassis "live". Powering it up with a variac while measuring the chassis to ground potential (AC) would be the route I would take with it. You'll have to reform the main capacitors, or replace them if they have too much leakage. That's better than killing the power transformer.
Once fixed, these tend to sound really good. Everything technical posted to this point is correct. The only things to watch are fragile components and fragile traces on the PCBs. The switches may have a copper pattern PCB for the contacts, so you have to watch for corrosion there. If you try cleaning the switches, make absolutely sure you don't get any cleaner into either tuning capacitor, or any of the trimmer caps. The markings on the glass will come right off as well. Clean that by very careful blotting it off with clean water moistened smooth cloth and be patient. Spray it with any cleaner and you'll watch the markings slide down the glass.
Nice project there, and you now have the class A amplifier you wanted to experiment with!
-Chris
I may possibly have a diagram for it. I'm not sure, but I have some collections that may include it. The offer that davorin made to you is something you should look into. I trust that what is odd for us is very normal for him in the way of service information. Just like "the all American five" sets are to us over here.
It does have a power transformer that should isolate the chassis from the AC mains, but there may also be a small capacitor that has shorted that can make the chassis "live". Powering it up with a variac while measuring the chassis to ground potential (AC) would be the route I would take with it. You'll have to reform the main capacitors, or replace them if they have too much leakage. That's better than killing the power transformer.
Once fixed, these tend to sound really good. Everything technical posted to this point is correct. The only things to watch are fragile components and fragile traces on the PCBs. The switches may have a copper pattern PCB for the contacts, so you have to watch for corrosion there. If you try cleaning the switches, make absolutely sure you don't get any cleaner into either tuning capacitor, or any of the trimmer caps. The markings on the glass will come right off as well. Clean that by very careful blotting it off with clean water moistened smooth cloth and be patient. Spray it with any cleaner and you'll watch the markings slide down the glass.
Nice project there, and you now have the class A amplifier you wanted to experiment with!
-Chris
Thats what got me here too....
Third set I got into...
First was an old RCA Victor, circa 1960 One channel Tube power, lazy days listening to my fathers LPs' Grand Canyon suite.
The 6.3s lighting up the interior of a cherry wood topset.
Open back...the cardboard perf-board me long since taken off my my prying eyes. Took the amp unit out to wonder at....didn't know about stored voltages.
Twelve inch Three-way. Thought I had a dual channel amp.
In 1966 my folks got a Sony reel-to-reel TC-200...............stereo. "66" it was exotic. 7/12 inch.....learned to do A chipmunk Radio series, recording & speeding up..wound up erasing that track......boo.
The capstan drive humming along......beautiful sound.
Went to school at 28'........Learned all about & Got a Degree AAS-EET.
Worked as an Auto Tech for 25 Yrs.........Got "invited" to the CIA.....stupid me I told everyone about my 'Brochere'(SP?), wasn't suppose to say at work "Hey I got a packet in the mail from the CIA" I coulda been slogging thru a Nicaraguan jungle by now Writing technical texts for "In country ops'"
A AA in Journalism & a AAS-EET...........A G man!!!!!
Till one day, at work a guy in the Bodyshop brings me an old tube radio....1950. Reverting to my Electronics mindset I take & listen & hear a 60Hz....bad PS sound.....scrounge backside & I jump the PS cap with another 5uF, 450V I had on tap & low & behold she cleared up...just fine now. So I wrapped up the cap in mountains of 600V tape & stuff er back in.
First was an old bakealite, brown, that kept me company when I was six or so down with....mumps?
I doth ramble...Don't I....
So who has the prettiest missus?
_____________________________________________________Rick......
Third set I got into...
First was an old RCA Victor, circa 1960 One channel Tube power, lazy days listening to my fathers LPs' Grand Canyon suite.
The 6.3s lighting up the interior of a cherry wood topset.
Open back...the cardboard perf-board me long since taken off my my prying eyes. Took the amp unit out to wonder at....didn't know about stored voltages.
Twelve inch Three-way. Thought I had a dual channel amp.
In 1966 my folks got a Sony reel-to-reel TC-200...............stereo. "66" it was exotic. 7/12 inch.....learned to do A chipmunk Radio series, recording & speeding up..wound up erasing that track......boo.
The capstan drive humming along......beautiful sound.
Went to school at 28'........Learned all about & Got a Degree AAS-EET.
Worked as an Auto Tech for 25 Yrs.........Got "invited" to the CIA.....stupid me I told everyone about my 'Brochere'(SP?), wasn't suppose to say at work "Hey I got a packet in the mail from the CIA" I coulda been slogging thru a Nicaraguan jungle by now Writing technical texts for "In country ops'"
A AA in Journalism & a AAS-EET...........A G man!!!!!
Till one day, at work a guy in the Bodyshop brings me an old tube radio....1950. Reverting to my Electronics mindset I take & listen & hear a 60Hz....bad PS sound.....scrounge backside & I jump the PS cap with another 5uF, 450V I had on tap & low & behold she cleared up...just fine now. So I wrapped up the cap in mountains of 600V tape & stuff er back in.
First was an old bakealite, brown, that kept me company when I was six or so down with....mumps?
I doth ramble...Don't I....
So who has the prettiest missus?
_____________________________________________________Rick......
Attachments
Hi George,
Russian tubes aren't bad, but not all Russian tubes are good. The practice of remarking a Russian tube to the closest American number is unfortunate, but that is the only way they could sell them. The actual tube choice is probably your biggest problem. The Sovtek tubes (these are Russian tube types remarked as US numbers) normally stand up to normal use fine, but the characteristics will be different for sure. Other than that, good tubes. I've also seen some horrible Chinese tubes (actually the worst I've seen!) where the elements in side were skewed all over the place, marked as US numbers.
I am curious where you got your 7189s from that were improperly marked. If you could PM me, I'd appreciate it. I'll not advertise that info. Didn't you have any in your warehouse?? Anyway, a serious problem since the 7189 is rated a bit higher than an EL84 or 6BQ5 type. Were the plates the normal size?
-Chris
Russian tubes aren't bad, but not all Russian tubes are good. The practice of remarking a Russian tube to the closest American number is unfortunate, but that is the only way they could sell them. The actual tube choice is probably your biggest problem. The Sovtek tubes (these are Russian tube types remarked as US numbers) normally stand up to normal use fine, but the characteristics will be different for sure. Other than that, good tubes. I've also seen some horrible Chinese tubes (actually the worst I've seen!) where the elements in side were skewed all over the place, marked as US numbers.
I am curious where you got your 7189s from that were improperly marked. If you could PM me, I'd appreciate it. I'll not advertise that info. Didn't you have any in your warehouse?? Anyway, a serious problem since the 7189 is rated a bit higher than an EL84 or 6BQ5 type. Were the plates the normal size?
-Chris
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Joined 2009
Paid Member
Thanks for the all the help and interest !!!!!
It might be interesting to see if there are any differences between what you can find and what Davorin can dig up.
benb / Annatech, the PSU capacitor - I don't have any fancy equipment for reforming or a Variac. Perhaps I'd be better off removing the original, keeping it of course, and putting something modern inside ?
I'll take a careful look. I tried the push buttons, they don't feel as if the mechanical action is working well - i.e. they don't pop up cleanly when another key is depressed. I'm not sure about the electrical contacts by the physical behaviour suggests a clean is needed. Do you have a favourite cleaner type ?
My gosh, that could bring a grown man to tears. I hope you didn't learn the hard way about that one.
Missing volume knob - is there a place where people go to find replacements ?
That does seem to be the case - bodes well.
yes - got one of those !
Let's hope it works, if they are hard to find replacements that is...
It might be interesting to see if there are any differences between what you can find and what Davorin can dig up.
benb / Annatech, the PSU capacitor - I don't have any fancy equipment for reforming or a Variac. Perhaps I'd be better off removing the original, keeping it of course, and putting something modern inside ?
I'll take a careful look. I tried the push buttons, they don't feel as if the mechanical action is working well - i.e. they don't pop up cleanly when another key is depressed. I'm not sure about the electrical contacts by the physical behaviour suggests a clean is needed. Do you have a favourite cleaner type ?
My gosh, that could bring a grown man to tears. I hope you didn't learn the hard way about that one.
Missing volume knob - is there a place where people go to find replacements ?
That does seem to be the case - bodes well.
yes - got one of those !
Let's hope it works, if they are hard to find replacements that is...
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"Missing volume knob-is there a place where people go to find replacements?"
Try www.surplussales.com They have all sorts of surplus & odd-ball stuff, like radio knobs for 30 YO HAM radios & the like...try em you might find something close. Or doable if you wanted to change all of them for a slightly different look.
__________________________________________________________Rick.....
Try www.surplussales.com They have all sorts of surplus & odd-ball stuff, like radio knobs for 30 YO HAM radios & the like...try em you might find something close. Or doable if you wanted to change all of them for a slightly different look.
__________________________________________________________Rick.....
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Ei definitely not in tubes business
There are still a few places in Europe where Ei EL84 can be found (one raised the price from 9 to 14 EUR a piece a couple of months ago, a few others still have them at EUR 9.50 - VAT included). The stock varies from those once sold as Siemens OEM (could even be pre-1990 made) to year 2000+ production with smudged print. I've also come across 6CA7 for EUR 30 and a few remaining 12AX7.
Ei stopped tube production in 2006. Assets were (supposedly) subsequently sold to Western Electric but no production has resumed so far.
There are still a few places in Europe where Ei EL84 can be found (one raised the price from 9 to 14 EUR a piece a couple of months ago, a few others still have them at EUR 9.50 - VAT included). The stock varies from those once sold as Siemens OEM (could even be pre-1990 made) to year 2000+ production with smudged print. I've also come across 6CA7 for EUR 30 and a few remaining 12AX7.
EM84 are not hard to come by, these are very common "magic eye" tubes in European gear. On top of everything a Soviet drop-in replacement exists (no circuit tweaking required).
Actually I can't think of a single "magic eye" tube in noval form factor that wasn't the "side view" type ...
When you decide to start tinkering with your radio by all means stay clear of IF transformers and their tuning screws if you don't have suitable gear to retune them.
Hi Bigun,
Well, there are tons of schematics around here, and many on the web as well. Try "Nostalgic Air" as well. Anatoliy is probably also correct. As many radio designs are similar, if not the same here, so it goes in Europe I bet.
I think I have a variac you can borrow. I have a few that we could trade for if you want, the same as I use on my bench for most of my work.
Your push buttons probably need lubrication in the mechanical section as well as a contact clean. Some contacts need a lubricant on top to protect them from excessive wear - like a volume control (hint all you cleaner sprayers!). The contact cleaner I use depends on the details. I like either De-Ox-Id (General Cement) and also DeoxID (Caig).
It did. Don't make the same mistake I did way back then (in the 70's or late 60's - can't remember that long ago for an exact date)
EM84's aren't that bad to find. I agree with Arnuf on this. All are side view that I've seen. If you look at older tube tuners, you will see these side view types. The old radios used the round ones. R-R tape decks may have either style (depending on age) to indicate sound level. A zero mass indicator like Alpage tried to bring back in one of their cassette decks.
-Chris
Well, there are tons of schematics around here, and many on the web as well. Try "Nostalgic Air" as well. Anatoliy is probably also correct. As many radio designs are similar, if not the same here, so it goes in Europe I bet.
I think I have a variac you can borrow. I have a few that we could trade for if you want, the same as I use on my bench for most of my work.
Your push buttons probably need lubrication in the mechanical section as well as a contact clean. Some contacts need a lubricant on top to protect them from excessive wear - like a volume control (hint all you cleaner sprayers!). The contact cleaner I use depends on the details. I like either De-Ox-Id (General Cement) and also DeoxID (Caig).
I was young.
It did. Don't make the same mistake I did way back then (in the 70's or late 60's - can't remember that long ago for an exact date)
EM84's aren't that bad to find. I agree with Arnuf on this. All are side view that I've seen. If you look at older tube tuners, you will see these side view types. The old radios used the round ones. R-R tape decks may have either style (depending on age) to indicate sound level. A zero mass indicator like Alpage tried to bring back in one of their cassette decks.
-Chris
Just a few notes, please don't take "I haven't seen it" (said by me or anyone else) to mean something is rare or expensive or whatever. For one thing I'm in the USA and I'm guessing the linear magic eye tubes weren't used as much here as elsewhere.
Another note, poling around I found the Mother Lode of info on these things:
All About Magic Eye Tubes
Another note, poling around I found the Mother Lode of info on these things:
All About Magic Eye Tubes
Also, not just the gear, but also the knowledge of how to align a superhetrodyne receiver.
That sounds good to me. If there's enough room for both, just disconnect the original (you only need to disconnect the "+" connection(s) underneath) and wire in the new one wherever it will fit.
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Joined 2009
Paid Member
I have to temper my enthusiasm - I have to finish putting the guts back inside my Cellini amp or it'll never get finished - it's been lying there for over a month and it's supposed to be my first tube amp and I've only heard it once. Once that's done I'll start work on the 'Florida' and post back here.
I have to say it's great to have so many helpful souls in this venture.
I have to say it's great to have so many helpful souls in this venture.
Hi Bigun,
Well, you know where to find me. I don't run fast these days either!
Hi Benb,
-Chris
Well, you know where to find me. I don't run fast these days either!
Hi Benb,
Not a stupid question at all. You first need to find out what IF frequency the set uses. There are many sources of good information on the web. Some of the links that Anatoliy posted look interesting. The last one listed is new to me, but the links seem to be down at the moment there.
-Chris
Member
Joined 2009
Paid Member
Hi,
Thanks very much Davorin - I'll take a good look. If the images you have are a bit clearer but were too large to post, can you PM-me and we'll work out a way for you to email them to me.
Edit: I just printed them out. Wow, it's a complicated circuit. There are symbols on there I don't recognize. I'm going to have to take my time. Heck, maybe it'll work first time I power it up.
Thanks again guys -
I'll let you know how it goes...
Thanks very much Davorin - I'll take a good look. If the images you have are a bit clearer but were too large to post, can you PM-me and we'll work out a way for you to email them to me.
Edit: I just printed them out. Wow, it's a complicated circuit. There are symbols on there I don't recognize. I'm going to have to take my time. Heck, maybe it'll work first time I power it up.
Thanks again guys -
I'll let you know how it goes...
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