Emerson AX-212 - First Power Up Attempt

Powering up the Emerson AX-212 for the first time after replacing the defective capacitors, resistors and adding a rectifier diode and power resistor to the 300mA Heater string. In addition, a Zener Diode and shunt resistor was added across the Type 44 Dial Lamp. The RF alignment and a few other misc. things are still pending.
Thanks for watching and subscribing to my channel on vintage radio repair.
The playlist for this series:
kzbin.info/aero/PLjLu4V-71S1ItzQs1zhg3Ja5Lk7lRHBXc

[@jimdawes7261]

It's a wonderful experience when the radio works at first power-up and a not so wonderful experience when it doesn't, glad this one worked. Enjoying this series. I need to learn about this Zener diode application for the dial lamp.

[@RestoreOldRadios]

Yep, when nothing happens is disappointing, but this provides an opportunity to improve my troubleshooting skills and learn something new. With that said, I’m sure glad this gem plays. Check out John's post on the ARF: antiqueradios.com/forums/viewtopic.php?t=115812&postdays=0&postorder=asc&start=220 Thanks for watching. Best, Don

[@RestoreOldRadios]

A few videos you may find helpful as well. kzbin.info/www/bejne/e2Wsepx_na6Md8k kzbin.info/www/bejne/hGq4daKYlteBnrc

[@nor4277]

Nice job this radio good for another 50 years.very clean

[@RestoreOldRadios]

Hi Ron - thank you my friend. I hope you’re doing well. Best, Don

[@AllAmericanFiveRadio]

Nice work. It's still an amazing experience when hear an old radio come back to life.

[@RestoreOldRadios]

I truly appreciate it Rick. Hearing one of these oldies play again is exciting and enjoyable. Thanks again for watching. Best, Don

[@nor4277]

Your work is always well thought out and very clean ,and safe.my hate off to you .

[@RestoreOldRadios]

Thank you Ron, much appreciated. Best, Don

[@GeorgeChristofi]

That is really nice and sensitive on low voltage. I should have put in the Zener diode on the Bush I just finished because they are notorious for taking out panel bulbs at startup. Looking forward to the next part Don. You take care and look after yourself. George.

[@RestoreOldRadios]

Thank you George. It’s never too late to throw a Zener in the circuit. I appreciate you following the series. Best, Don

[@armandcorpolongo]

Don: Good video and great tip on the diode and dial light. It should save me from having to replace them so often. Great sounding radio for such a compact set.

[@RestoreOldRadios]

Thanks Armand. I’m looking forward to getting it back in the cabinet and see how it sounds. Thanks for watching. Best, Don

[@rayislooking2]

Great work Don. A joy to watch you work. Thanks for sharing.

[@RestoreOldRadios]

Thanks. It was tedious, but rewarding to hear it play again. Best, Don

[@cristrigotti9933]

Very good! Glad it is working out for you.

[@RestoreOldRadios]

Crist - I was not overly optimistic it would play since I skipped checking the coils. The one I.F. Coil looks a little rough. Thanks for watching. Best, Don

[@Backtothefutureradios]

Great job Don! The zener mod is very nice, those bulbs usually go bright to dim. Its a wonder any bulbs survived back in the day! Thanks for sharing....Take Care--Larry

[@RestoreOldRadios]

Thank you Larry. The bulbs were stressed for sure. Hope your workouts are still going well. It was like summer here over the past few days. Take care of yourself. Best, Don

[@YouAllKnowBob]

Sounding great. And no parts left over that wouldn't fit back in! 👍👍

[@RestoreOldRadios]

Bob, known I showed on camera. LOL Have a wonderful weekend and thanks for watching. Best, Don

[@AMStationEngineer]

The EAS Alert, was one helluva way for that radio to awaken from its slumber, which probably had its beginnings during the Eisenhower Administration.

[@RestoreOldRadios]

Tim, that was weird; a local station at 600KC. I had no idea I had the tuning... in that location. Thanks for tuning in for the EAS Alert. Best, Don

[@AMStationEngineer]

One of the last transmitters that I performed complex repairs on, was located 30 miles west of Philadelphia, and still had the CONELRAD frequency changeover system intact, but deactivated. But the strangest "facet of broadcast technology" that I've ever seen, was a second "stand alone" Collins 5KW transmitter, at 1240Khz, which had its very own building, and an enclosed 'snowplow shaped' unifocal antenna, which was between 10' and 15' in elevation; contained three counterpoise earthing systems, two of which had 50-gallon tanks which at one time held a 30%/30% combination of sodium chloride and Magnesium Sulfate that provided a "salted counterpoise". My best estimation, is that this system was a "ground wave enhancement system", which was designed to pump a receivable AM signal at low elevation, directly towards Center City Philadelphia, in the event that the Strata became ionized. Til this day, it's so very puzzling - as to the true purpose of this system, and let me tell you, this system was built to one damn tight specification.

[@RestoreOldRadios]

That’s a cool read. Wonder who designed it?

[@LarryDeSilva64]

Nice job cleaning that old radio up Don. Sounds pretty good too.

[@RestoreOldRadios]

Thank you. I should have removed the cardboard from the speaker, but I didn’t want to chance damaging the old brittle speaker cone. Thanks for watching. Best, Don

[@greggsvintageworkshop8974]

Great work Don! Sounds really good, considering you haven't tuned it yet.

[@RestoreOldRadios]

Yep, a much better player than I expected on the first power up. Thanks for watching Gregg. Best, Don

[@BretFrohwein]

Nice use of the zener's.. interestingly. a few years back when I was working on a Philco PT6, it would blow the lamp out periodically as you mentioned and most definitely if I turned it off and back on while the tubes were still warm. I tried the zener trick and I got trolled on the ARF for it. I kind of feel vindicated. ;-)

[@RestoreOldRadios]

Bret - thank you. I know purist are not inclined to use them in a vintage radio and I recognize that. It certainly works and provides a solution that can be utilized when needed. Thank you for reaching out and for watching. Hope all is well with you. Best, Don

[@deanschmeltzer9620]

Thanks Don for another fine video . Like it when you take time to explain things. The diode is really neat . What makes the zener special?

[@RestoreOldRadios]

Thank you Dean. The Zener Diode acts as a voltage regulator and keeps the voltage across the dial lamp below or at 6.3V. The Tube Heaters when cold as the radio is first powered up have a low resistance and this causes the Heater string voltage to be high. Since the dial lamp is in series with the tubes, the dial lamp voltage can exceed 8 volts on power up and this will shorten the life of the bulb or can cause it to blow. The Shunt Resistor is added to make the dial lamp, which in this case is rated at .25A match the .30A heater elements for the tubes used in this particular receiver. Check out this article at: www.electronics-tutorials.ws/diode/diode_7.html Thanks again for watching and I hope this helps. Best, Don

[@RestoreOldRadios]

A few videos you may find helpful as well. kzbin.info/www/bejne/e2Wsepx_na6Md8k kzbin.info/www/bejne/hGq4daKYlteBnrc

[@i82996]

Question: I have been using inrush current limiters, but of course the units I work are far roomier than this little set, and heat dissipation is an issue for the unit you are restoring, did you consider using one, or is there another issue with using one on so simple a radio?

[@RestoreOldRadios]

Albert - I've used a CL-90 Thermistor in a number of my projects. The chassis was so tight underneath (heat would have been a concern) and I used the open space on top for the rectifier diode and power resistor. Which one do you use? Best, Don

[@i82996]

@@RestoreOldRadios In the Hallicrafters I restored, I used 120 ohm current limiters (Ametherm MS22 12102 Inrush Current Limiter )which give a nice slow warm up to the tubes and limits B+ inrush current to the B+ components and lowers the overall AC voltage by about 1.5 volts, which is closer to the original design specs of 115 VAC. I am sure the pilot bulbs dont mind it a bit either. But there is lots of room to work with and allow heat dissipation. My only question on using them is how long they last before they fail since I rebuild the units to last hopefully 10-20 years. Also I mount them as the last thing before the power transformer primary leads (1-fuse, 2-safety cap, 3-switch), lots of room to do all that. Currently working on an SX-71 but learning all I can from your videos on prechecks before starting it up.

[@RestoreOldRadios]

A good question for the vendor(s) on the life expectancy of the device. They will probably say it depends on the frequency of use and proper loading to stay in the design window. I see the MS22 12102 has the same specs as the CL-90. You may want to reach out to Tim KZbin +AMStationEngineer or Rick +AllAmericanFiveRadio and get their expertise on current limiters. Best of luck on your projects and if you hear back or learn more on the life..., please keep me posted. Best, Don

[@BobbyTB425]

That's tight in the chassis. Packing a lot in a small space, but I know you can get it in top working order. Why is cardboard in front of the speaker? Is it for protection

[@RestoreOldRadios]

Thanks Bobby. The cardboard is to help keep my fingers out of the speaker cone. So far, so good. Thanks for watching. Best, Don

[@Madness832]

Get a reproduction cloth-covered cord & reuse the acorn-cap plug.

[@RestoreOldRadios]

I agree. Thanks for watching. Best, Don