Category: Zenith royal 20 transistor radio

They were the most copied radio ever made, but they were never matched by any imitator. There were over a dozen models in the series…a few of the lesser models featured 6 or 7 transistor chassis and a faux-leather covering called Permawear which has not held up well over the years. All were top performers, featuring 8 transistor chassis, three-gang air-core variable tuning capacitors with vernier tuning and a tuned RF stage for top reception quality.

Yes…these were deluxe radios. That switch disabled the AGC Automatic Gain Control circuit, which normally compensates for signals of varying strength to keep reception as constant as possible.

By turning the AGC off, it was much easier to use the radio as a direction finder to home in on a navigational beacon or a local radio station…when you turned the radio to null the signal, it would be pointed directly at the transmitter. Zenith ads of the day showed yachtsmen and aviators carefully adjusting their Navigators to find their way home.

The most striking improvement was the introduction of the slide rule dial which was much easier to read than the small circular dial of the earlier sets. Zenith usually had many more minor variants within the major models with different chassis numbers, transistor complements and minor assembly differences. The three pictures above show the major versions of the Royal The Royal Navigator was similarly upgraded to the Royal YG with the addition of slide rule tuning. This and all future Navigators were produced only in black.

Later on Zenith would come up with confusing model numbers for their Navigator upgrades. And with the rotating ferrite the radio could remain stationary while you used the sites built into the rotating antenna, making these last Navigators excellent navigational tools. Later on the Royal 97 Navigator would replace the YM…with the exception of the model designation on the nameplate these radios look identical on the outside and perform similarly but have minor circuit changes.

I should also point out that as I have worked on and researched vintage radios I have often seen manufacturers change the transistors and other components used in their sets but generally this was not done to change performance. They usually made these changes to utilize whatever components were readily available to them at the time. Sometimes this would be reflected in a new chassis number or would be documented in a new Service Manual or an addendum, but not always.

It had a badly deteriorated battery box due to battery leakage and very common in these old radios and although I was able to grind the rust off its contacts and make it work, there was so much metal worn away that I eventually replaced it with a battery box from a parts donor set. The radio was still playing very poorly though…weak audio and reception, similar to what you might expect with weak batteries.

Fortunately this is usually easy to remedy in these radios by replacing the electrolytic capacitors…the single most failure prone device in them. This radio has only four in it and disassembly is easy for access to them. At the time I first worked on this radio I unfortunately did not have a capacitor checker, but it was fairly simple to replace those electrolytics, then check for proper operation after each one was replaced.

Eventually a friend strongly recommended a fantastic capacitor analyzer meter he uses…the EDS88A:. What really attracted me to it is that it can measure an electrolytic cap without removing it from the circuit and it has therefore paid for itself in more efficient use of my time many times over. In the case of myI learned that one of the replacement caps I had put into it was bad!The Zenith Royal was one of the longest running transistor radio series.

During those 10 years, it went through 7 styling changes and several performance improvements. They were known for their superior performance and the early ones were powered by seven transistors when most other radios used only 4 or 5. These were rather large pocket radios measuring 5. So you can still enjoy listening to them. For the collectors who enjoy taking a step back in time while listening to their classic, I recommend that you choose a Zenith Royal After all, why not get the top of the line?

They are fairly easy to find in good operating condition and reletively inexpensive to obtain. In the pages that follow, I will share with you some of the examples I have been able to collect and the information I was able to gather about the Royal line. Just click on one of the links below to start your tour.

Once inside, remember to click on a photo to enlarge it, then click again to make it life sized. The Royal B with printed circuit board — Introduced in mid This allowed for faster production to keep up with demand. The Royal D — Introduced in An 8th transistor was added along with other chassis enhancements so was the Long Distance designation.

Enhanced D — Late The grill changed from concave to convex to allow room for the new expanded range speaker. Same great long distance chassis, but these are hard to find in nice condition. The gold plating by the knobs did not hold up. The Royal H — This all new innovative transistor radio would set a whole new standard for performance. With an large expanded range speaker with an off-set coil was capable of producing crisp highs and deep lows for a listening experience not hear before in a pocket radio.

Although still a sharp looking radio, the output fell back to milliwatts, the speaker was reduced in size, and the quality of sound suffered.

It was cheaply put together and performance took a big step backwards as the output was only half of the model H. Needless to say, this one is not sought after by collectors, except maybe as a filler to complete the line. Sad way for this legendary product line to end. It did feature a lighted dial though by pressing the button on the lower right which was kind of nice.

This marked the end of the Royal series. I purchased it from the original owner.The first 20 minutes of the scale on the bezel are in red Using the telemeter scale on the rehaut, the edge of the dial, you can calculate distanc Models from the 90s often cost less than 3, euros Current versions of the Zenith El Primero Stratos Flyback Rainbow are.

Royal Enfield posted a sales of 70, units for the month of September The company recorded a growth of 22 per cent for the same. Zenith Named for the word "zenith", which means the highest point reached by a celestial body in the sky, the Zenith company has accumulated 1, awards for precision in watch-making Founded in by Georges Favre-Jacot in Le Locle, Switzerland, Zenith was the first company to unite every step of watch production in a single building, a.

Royal Enfield was established in Oman back in The first model to exit the production line in Oman was the Bullet InRoyal Enfield teamed up with Eicher Group, post which the brand launched the Classic range in But don't despair! Some elbow grease, patience and a few hours work will soon have your ZTO playing and looking like new ' Like new ' is a phrase to remember here for we must make some decisions as to what we want from our 'new' ZTO Some folk say there is a 'sliding scale' to describe the level of restoration Television History - The First 75 Years [All USA Sets] [Master Index] Zenith - USA Dealer Advertising Brochures: [need photo][need photo] - TH 21" console, composite cherry wood"Model X" [need photo] - TR 21" console, composite mahogany grain"Model X".

Electronics service manual exchange : schematics,datasheets,diagrams,repairs,schema,service manuals,eeprom bins,pcb as well as service mode entry, make to model. If you are interested in our company or products, welcome to visit our company or local offices; you can also get contact with us through online consulting, demand table submission, e-mails and telephones. Useful Links cement kiln drawings crushing screening sand product pdf mills minerals ore in gold mining nz stone bowl with crusher.Zenith Royal Posted: Apr Sun 25, pm.

Does anyone know of a battery that will work fit in this radio or will I have to use button cells is series? The batteries are still available from Mouser, Allied and others. It takes 2 of them. Doubt they are still mercury type now.

Old number was RM Posted: Apr Mon 26, pm. Thanks alot Jim, That's the information I needed. The radio plays quite well. I powered it up with 2 AA batteries. Posted: Apr Tue 27, pm. I am curious as to using an "N" cell? They used those in HP41 programmable handheld calculator. Posted: Apr Thu 29, pm. Cliff, I think the N cell is too big. These 's are.

zenith royal 20 transistor radio

Only problem capacity is listed ma and old mercury type was ma. Posted: Jun Mon 11, pm. Someone on eBay is selling adaptors--cups made of machined brass. All you do is drop in a hearing aid battery and you're ready to go. Here's mine, using two 1. Posted: Jun Fri 29, pm. If you check on eBay, there is someone who makes adapters--same size and diameter of the originals, but they're hollow on top--you drop a hearing aid battery into them.

I have them in my Micronic Ruby as I type this--look and fit perfectly. Posted: Jun Sat 30, am. Posted: Jun Sat 30, pm. I just get them from PKCell along with other sizes I need, usually about 10 - 15 dollars an order.

In real money it would be a lot less I'm not too keen on using nuts and bolts as spacers. Posted: Jul Sun 01, pm. Posted: Jul Wed 04, pm.

zenith royal 20 transistor radio

Posted: Jul Thu 05, am. Look at the picture and you will understand why they soldered these blue wires: they used it for alignment procedure at the factory. Posted: Jul Thu 05, pm. Post subject: Latest projectlittle bitty Zenith Royal 20 viewtopic. Page 1 of 2. Previous topic Next topic.Our new search experience requires JavaScript to be enabled. Please enable JavaScript on your browserthen try again.

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The Zenith Royal 500 Family

Vintage Transistor Radio Zenith R TransOceanic Radio 4. Not Specified Brand see all Brand.Zenith Royal 20 Service Info Needed. Posted: Aug Sat 22, pm. If anyone has any service info for a Zenith Royal 20 please contact me. Any help would be greatly appreciated.

I found this schematic for the Royal Posted: Nov Fri 30, pm. I have a Zenith Royal 20 and would like to repair it but the schematic you attached is a little to fuzzy when I open it.

Can you re-attach a higher resolution version of the Zenith Royal 20 schematic? Posted: Dec Sat 01, pm. The image resolution is x pixels and I don't have anything higher. I can read it fine as it appears in my post on my 13" laptop screen.

Have you tried zooming in? This one?

zenith royal 20 transistor radio

Scaling UP is also sometimes called "up-sampling". This does not increase the information content, but smooths things out so other enhancements work better. Hi pixellany, I use e a very good program called Ifanview that is completely free to enlarge pictures and schematics. Then select Set New Size and put in for the width and for the height. Then click on File on the program menu and select Save As on the pull down menu. You then will choose what format that you want to save it in I usually choose.

The schematic will not be perfect but it should look much better. Page 1 of 1. Previous topic Next topic. Dave Doughty. Attachment: Zenith Royal 20 Sch. New Member. Users browsing this forum: No registered users and 8 guests.The technology was new and exciting. There had already been tube-based portable radios but the greater bulk and power requirements of a tube design meant that the radios needed larger, more expensive specialty batteries which kept most tube radios larger and more expensive to run.

Transistors were a post-World War II development and when they became practical, shirt-pocket-sized radios became possible. Even larger radios which could offer better reception and sound could now be powered by common flashlight or penlight cells. In November Zenith, drawing on its pioneering work in hearing aid miniaturization and transistor design jumped into the transistor race with their Royal Most radios in cars, on kitchen counters and night stands, were AM only.

One of the reasons the performed so well was that Zenith manufactured many of its own components rather than using generic parts which would compromise performance. The radio had a clever three-position bail handle which could swivel back to prop the radio at a nice angle, lifted straight up to become a carrying handle, or folded down out of the way against the back of the set. Zenith marketed these radios aggressively and additionally offered attractive gift boxes as an add-on option.

Zenith was proud enough of their new model that some were released in a semi-transparent maroon case, so in bright light you could see through it. While some early transistors did suffer a higher defect rate than later ones, transistors turned out to be very stable and reliable.

We have since learned that transistors are usually longer-lived than the electrolytic capacitors which often require replacement in vintage electronics. Those early days of transistor technology saw rapid development so manufacturers, including Zenith, updated their models frequently. In the hand wired chassis gave way to a modern printed circuit board PCB design with chassis 7ZT40 and 7ZT40Z1, along with the addition of vernier tuning.

A big improvement came in with the release of the Royal D the D stood for Distance. Now featuring 8 transistors and chassis 8AT40Z2 a new RF amplifier stage was added along with other improvements providing better reception and stronger sound. There was also a newly designed speaker called the inverted cone which was convex rather than concave which helped Zenith achieve better sound quality.

In fact, while the remained the flagship of the portable line, Zenith introduced many smaller, less expensive sets, some of which were great performers for the money. The owl-eye knobs were gone replaced with thumb-wheels and an ingenious new 3 x 5 extended range speaker was introduced which elevated the audio quality to a whole new level for this size radio.

The new cabinet design highlighted this speaker and Zenith featured it in their advertising. The new speaker was powered by an amplifier which put out more than three times the power of the previous …Zenith really went all out to keep their top of the line pocket radio a top performer.


The H was produced throughafter which the series started a downhill slide. These were somewhat cheapened chassis fit into the existing E and H cabinets, so you have to look inside to see if you had an old or new model.

They were still decent performers but were a notch below their predecessors. Minor Variations: Repair technicians know that even within the main versions of any given model there were often minor changes and upgrades made along the way, and Zenith was no exception.