Restoring a vintage Kriesler console radio

Discussion in 'Electronics & Electrics' started by mjunek, Apr 3, 2019.

  1. mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    Hi again everyone!

    Welcome to my worklog for restoring a Kriesler 11-9D console radio.

    This will be the third radio that I have embarked on restoring.

    The first was an AWA Radiola 517-M mantle radio from 1948, and I put together a worklog.
    The second I've yet to do a worklog on, but that's coming soon!

    A bit of history - this radio was built in either late 1947 or early 1948. The Kriesler factory was based in Alice St, Newtown, which is now a block of units near Matt Hogan reserve. It is both a medium wave (broadcast band) and shortwave radio, with a line-up of 5 valves for its operation.

    I found this radio going for a relatively reasonable price on Gumtree, and so I bought it. My wife has now claimed that it is my birthday present from her :)

    Internally, the Rola speaker is dated 14 November 1947, which is why I'm not 100% on the manufacturing date. The ARTS&P label, however, is light blue with no prefix, which according to research suggests 1955 onwards, which is a little surprising. For those that are unaware, much like the UK still has today, all Australian radios and Televisions used to be licensed. This was to ensure that the patent royalties were paid to the people that came up with the technology. This ceased in 1974 with the advent of colour TV.
    For some further reading on the licensing and labels - see this page

    In regards to this radio, however, it looks to be in original condition - I haven't yet taken the chassis out to inspect underneath, however I can see the original electrolytic capacitors still in place.
    The previous owner had butchered on a power cord (twist and tape) and told me "it works and tunes in one or two stations" - which I'm hoping means that nothing has gone boom inside. I'm guessing the original paper capacitors are still in there.
    The speaker has a small hole in the cone - when I get further into breaking down the unit, I'll get a better look at it. Hopefully nothing serious.

    The timber work has the usual signs of age, but still in better nick than my 20 year old coffee table!

    All in all, I am already loving this radio, despite having not gotten into the guts of it yet.

    Before I continue with the restoration, I'm going to put my obligatory warning message up:

    WARNING: Valve radios and televisions contain voltages that can deliver lethal shocks. You should not attempt to work on a valve radio or other electrical appliances unless you know exactly what you are doing and have gained some experience with electronics and working around high voltages. Under no circumstances should you ever apply power to a vintage radio, television or other electrical appliance you have acquired without first having it checked and serviced by an experienced person. Also, at no time should any appliance be connected to an electricity supply if the power cord is damaged. If in doubt, do not apply power. Some of the components, coming on 70 years old, are guaranteed to be bad. You could eleectrocute yourself, potentially have components exploding and starting fires. Please take note!

    Now - some photos of it as it has arrived-

    In all its glory
    [​IMG]
    [​IMG]

    Timber work has marks, not bad for 70 years of hanging around a house!
    [​IMG]
    [​IMG]

    Chassis
    [​IMG]

    Valve Lineup
    [​IMG]

    ARTS&P Label
    [​IMG]

    Speaker - Manufacturing Date & Tear
    [​IMG]
    [​IMG]


    Stay tuned for more posts!
     
    elvis, Tinian and Agg like this.
  2. Symon

    Symon Castigat ridendo mores

    Joined:
    Apr 17, 2002
    Messages:
    4,532
    Location:
    Brisbane QLD
    Will watch this thread with interest, also enjoyed your other thread. My grandfather (a technician for the PMG when that used to be a thing) used to repair valve radios for pensioners in his spare time. I've been meaning to give one of these a go for ages but I know next to nothing about valves - it will be a good learning experience for sure.
     
  3. merlin13

    merlin13 Member

    Joined:
    Apr 12, 2003
    Messages:
    1,836
    Location:
    back in BrizVegas
    Lovely old cabinet, brilliant condition for it's age. Should be enough room in it to go all bastard and make it a sexy Geek case/media centre mod as well.

    *cough* Same Bat time, same Bat channel perchance?

    In your Disclaimer, I'd probably note that some old components can contain some nasty toxicities - Do Not Lick Fingers, Dispose Of Properly/Responsibly

    As my old instructors often quoted - Valves. Transistors with Pilot Lights. That Bite...
     
  4. Symon

    Symon Castigat ridendo mores

    Joined:
    Apr 17, 2002
    Messages:
    4,532
    Location:
    Brisbane QLD
    From what I've read it is the same theory of operation, just at much higher voltages. Should be fun.
     
  5. Tinian

    Tinian Member

    Joined:
    Jan 3, 2009
    Messages:
    17,002
    Location:
    15.0° N, 145.63° E
    Are you looking to replace just the cone or the entire speaker?
     
  6. merlin13

    merlin13 Member

    Joined:
    Apr 12, 2003
    Messages:
    1,836
    Location:
    back in BrizVegas
    Yes, fun indeed. Right up to the point you manage to poke a finger in the right spot and the heater volts jumps out to get you.

    Or even better yet in some of the older hardware - live chassis. THAT was always a good initiation for the workshop apprentice...
     
  7. Matthew kane

    Matthew kane Member

    Joined:
    Jan 27, 2014
    Messages:
    2,218
    Location:
    Melbourne
    Thank fuck for isolation transformers in the 70's.
     
  8. merlin13

    merlin13 Member

    Joined:
    Apr 12, 2003
    Messages:
    1,836
    Location:
    back in BrizVegas
    OH&S in the 70's? Shirley You Jest, you whimp... ;)
     
  9. OP
    OP
    mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    It's very rewarding bringing this stuff back to life. If you're electronics minded, it's actually not as difficult as it seems. I knew nothing about them either, but with a bit of reading, and trasposing modern day transistor knowledge onto the concepts, it's quite straightforward.
    And I'm definitely glad you enjoyed the other one, it's nice to know that it's worth sharing these experiences. I'll certainly make more posts and threads as time goes on, as this is definitely a hobby I'm starting to enjoy thoroughly.

    Yep - great condition cabinet. Wont be doing any bastard stuff on it, I much prefer to see these things in their original glory. That said, if the electronics was completely rat-shit, then I would definitely look at re-using the cabinet somehow.

    Absolutely - Stay tuned!

    Yeah good call. Oil filled caps with PCBs are the real nasties amongst the mix.

    Haha yep. Sounds about right.

    I'll probably repair the cone. I'll decide once I get it off the baffle board and see the ultimate damage. If it's just small hole/tear like that, it shouldn't be too difficult to repair.
    If you take a look at the other radio I repaired, you'll see there was next-to-nothing left of the cone. That was a cone replacement, as it was an electrodynamic speaker where the field coil also formed part of the power supply.

    The heaters in these radios are probably the safest part - as they are all 6xxx series valvles, they are running only on 6.3V. It's the plate voltage of the tubes, the B+ line, that's sitting up around 250 or more volts DC.
    I actually got bitten by the other radio due to not paying attention and brushing the resistor leg with the tip of my finger. I tell you what, there were a few choice words (not repeatable here) and I gave up for the night.

    That's one thing I'm always weary of. Fortunately we don't see too much of that in Australia. The All-American-5 radios were exceptionally bad at that, as were some AC/DC sets for country areas.



    As for the actual look-in, I'll be giving it more of a check this weekend once I clear up a bit of the garage space, so expect updates soon.
     
  10. merlin13

    merlin13 Member

    Joined:
    Apr 12, 2003
    Messages:
    1,836
    Location:
    back in BrizVegas
    Don't you dare butcher that cabinet - tart it back to original, even if you don't resurrect the old internals. Was suggesting more leaving it intact/as is (after making it all shiny again of course) and stuffing the newer hardware into it without touching the outside look at all.

    Hence the media centre idea..
     
  11. OP
    OP
    mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    Ahh, see, to me, the internals are what make it what it is :)
    As far as the restoration goes, it'll be a bit of TLC restoring the finish on the timber, and giving the existing circuitry an overhaul to make it reliable and safe.
     
  12. merlin13

    merlin13 Member

    Joined:
    Apr 12, 2003
    Messages:
    1,836
    Location:
    back in BrizVegas
    So run both the old valve hardware and the new stuff in the same box, Silly. I would - it'd look great sitting in the lounge room...

    Just not powered on at the same time.
     
  13. /invariance\

    /invariance\ Member

    Joined:
    May 23, 2012
    Messages:
    847
    Location:
    Brisbane
    Any ideas what that silhouette is near the speaker?
    Looks almost like a template for a much larger speaker.
     
  14. Alby1976

    Alby1976 Member

    Joined:
    Mar 1, 2002
    Messages:
    1,579
    Location:
    Mt Isa, again....
    Wow, that looks amazing as is, even better when done. Great job on the AWA.
     
  15. OP
    OP
    mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    Good question, I hadn't noticed it before until you mentioned it.
    I'll take a look at it next time I'm downstairs.


    As an update- yesterday I took the chassis out, and had a look inside. I'm really really surprised the thing didn't go BANG when the guys I got it from decided to plug it in. Every single paper capacitor was cracked.
    There was even a cobweb with a bunch of dead baby daddy-long-legs spiders in it.

    Today I replaced all the capacitors, and a few wires. Checked the transformer by powering it up unloaded, all windings working great. Inserted the rectifier valve, and brought up the power supply, B+ rose up to where it should be; no heat, no smoke, no bangs. Always a good sign.
    Then popped in the rest of the valves, and let it run for about 10 minutes on the bench at around 180V, doing nothing. Still no smoke, so very good.

    Connected it up to the speaker and managed to get a few stations tuned in. Sounded pretty decent, given I haven't even taken a look at the speaker yet.
    Switched out the dim bulb and brought it up to 240V. Then it started whistling and singing. That classic "wooo-eee-wooo" from the frankenstein movies as you change the tuning.
    Sounds like the IF alignment is a bit out of wack and there's some oscillation where it shouldn't be, and the AGC is kicking in and silencing it when tuned to a strong station.

    That'll be a job for the next week or so, I'll need to fire up the sig gen and CRO and see where it's going crazy.

    The under-chassis - all original
    [​IMG]

    Cracked capacitors. Plus our little baby spider friends
    [​IMG]
    [​IMG]

    Black rubber surround, completely hardened & cracked. Also molten into dial-lamps
    [​IMG]
    [​IMG]

    After re-capping. So much more room!
    [​IMG]

    The offenders
    [​IMG]

    And the oscillation I was referring to
     
    Last edited: Apr 7, 2019
    Tinian likes this.
  16. alexb618

    alexb618 Member

    Joined:
    Dec 15, 2004
    Messages:
    9,641
    Location:
    adelaide
    what tubes are in it? some of these old radios can be easily turned into awesome guitar amps.
     
  17. OP
    OP
    mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    The could, but given I am not a guitarist, I prefer to bring back their historic nature :)

    This one has

    ECH35 Hexode/Triode --- Mixer/RF
    6U7G Pentode --- IF Amplifier
    6SQ7GT Triode/Double Diode --- AF Amp / Detector
    6V6GT Beam Tetrode --- Power Amp
    6X5GT Rectifier
     
  18. OP
    OP
    mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    For those that are interested - this is the schematic for the Kriesler 11-9 .... as well as the changes for the 11-9D - the primary one being the 6B6G being replaced by a 6SQ7GT - essentially equivalent, but different pinout

    [​IMG]
    [​IMG]
     
  19. alexb618

    alexb618 Member

    Joined:
    Dec 15, 2004
    Messages:
    9,641
    Location:
    adelaide
    6v6 in the power amp is popular for diy guitar amps if the back to original doesnt pan out :)
     
  20. OP
    OP
    mjunek

    mjunek Member

    Joined:
    Apr 1, 2003
    Messages:
    868
    Location:
    Ashfield, Sydney
    I'll keep it as a spare for my AWA as it uses the same output valve too :)

    I've got a boatload of 6CM5/EL36 tubes, which I intend to make a stereo ~15W per channel hifi amp out of. And experimenting with some 6BQ6GTB's, which I should be able to get around 40W per channel push/pull.
    That'll be another worklog when I get around to it.
     

Share This Page

Advertisement: