- - - Or the second 1926 Neutrowound that looked like number 2.

From the post below, here is how the second Neutrowound receiver looked when it arrived - soaking wet.

Other than the rust, this one also had wasp nests inside, crunchy - dried out rubber tube mounts, open interstage transformers, missing on/off switch, missing knobs and no finish left on the wooden base.

I started off by sand-blasting all of the metal cabinet pieces and replating the corner trim and tube shields/caps.

This is one of those radios that needed to be taken entirely apart, each part cleaned, serviced/rebuilt and then reassembled.

I repainted the cabinet with wrinkle paint, which was easy since it was over 100 deg. outside. Having coated it twice, I just set it out in the sun and it wrinkled up just fine. It was then top-coated with black lacquer to bring up the gloss. CAUTION: lacquer will severely  mess up this wrinkle-paint. It must be applied really dry.

The base/board was stripped, filled and sanded then sprayed with shellac.

The rest just needed a lot of cleaning and the same re-stuffing of components that was performed on the earlier unit.

Fortunately, the missing knobs are similar to those used on a lot of 1920s radios. Unfortunately, I still need 5 of the tube shields/caps.

A couple of other notes:

Both of these radios were missing the 6 bolts that hold the top cover on and I'll bet this is quite common since reinstallation of these bolts takes a bit of  fishing. So they were probably left out having once been removed for service. If you need some, they are 4 inch long #10 X 24 machine screws with a slotted head.

If you need to replace interstage transformers, use 3:1 (three to one) rather than 5:1. If you use 5:1 transformers, you will probably end up overdriving the last audio stages. This will result in really noisy poor audio.  If you have a 5:1 with a tapped secondary, just use 1/2 of the secondary. That is what I did here.

If anybody find a few extra shields/caps, I could use a few. BTW they and the end trim are plated brass.

Russ

Sorry it has been so long since I posted. Honestly, if the smoke from the forest fires was not so thick outside, right now, I would probably be on my way to the shop.

About two months ago we were given a large collection of radios, chassis and parts. This was such a nice thing to do. The collector had just retired. He had a lot of projects and travel planned and did not want to liquidate the collection by selling individual radios.

So after two truck/trailer loads, there were radios stacked in the shop and at both the front and back doors.

Well, I may be a radio collector (hoarder), but I am also unable to allow stuff to pile up for very long. So for the past two months I have been cleaning, restoring, donating, selling and disposing of this collection. But, that is not what this post is about. The rest of that story will be posted later.


THIS story is about the two 1926 Neutrowound receivers that I acquired in the meantime.

Of the two, the one pictured above, was by far in the worst condition. Even though it was well packed, it arrived soaking wet. That probably did not account for the rust and bug nests, but it didn't help either. BTW, none of those tubes were good either. All of them had open filaments.

I am in the process of saving the specimen above. The greatest challenge will be finding the missing tube shields/covers.

For the moment, we'll concentrate on the other unit, below.

I won't take the time to illustrate the history of Neutrowound Radio Manuf. except to say that this division of Advanced Automotive Accessories only made radios for 4 or 5 years. This "Shielded Breadboard" design carried through those years with a few modifications.

Though this is a good radio, by 1926 the design was a bit dated. Then by 1928, the battery powered TRF was really behind the times. I can't really see why this design was popular in any of the years it was produced.

Pictures really don't express the size of this radio, measuring almost 3 feet long. It had 3 stages of tuning and the 3 dials rather than a single dial, as was becoming the standard of the time. I suppose that in a home that was yet to be "electrified" the need for batteries in 1927/28 was not a problem but elsewhere, the new AC powered radios were more desirable

.

Radio construction on a "breadboard" was quickly becoming a thing of the past.

There are two significant and nearly universal challenges to restoring any of these radios. The first is RUST. A crinkle coat paint was applied to the outer metal surfaces. In the 1927 models this could be a striking blue or red. In all of the models, adhesion - at least in the long term, was not so good. This lead to a lot of rusted cabinets  (see top pictures). Coupled to that, it seems that in the finishing process, shellac was applied (smeared) to the inner surfaces of the metal. This hit or miss finish led to rust on the inner surfaces as well.

The second and probably most encompassing issue is caused by the degradation of the gum-rubber mounting of the Kellogg tube sockets.

The first two tubes have somewhat of a "hard" mounting since the screws pass through the socket flanges, through the 1/4 inch gum-rubber and into the breadboard. The last 4 tube socket are fully floating on the rubber strip shown above having been replaced.

I have not seen an example of this radio where the rubber has not become powdered or at least the consistency of a sugar cookie. Needles to say, the rubber should be replaced. Gum-rubber sheet is not a common hardware item anymore and the cost of a piece may be significant. Mounting the sockets on new rubber is not an easy task either.

Above, I am holding an original piece of the rubber mount.

As you can see, mounting the sockets requires careful placement and compression of the rubber. This mount must compress the rubber without making a big hole in it, which would require starting over. I had to make a jig to hold the nuts/washers while compressing the assembly from the top. Otherwise, at least 3 (frustrated) hands would be required. By the time I made a few of these, the task was not so impossible, but at first it certainly seemed so.

Now consider what would happen if the sockets/tubes were not in the correct position.  You probably would not notice until you tried to replace the top cover and even more so as you tried to install the shields. In other words, incorrect placement results in the tubes hitting the top cover and/or the shields. The best you could hope for in this situation would be for the rubber base to give enough to allow the tube to fit through the hole at a slant - not acceptable.

Other common issues include failure of the 3 interstage transformers pictured in back, above. And, the replacement of the two .5 uf paper capacitors. I restuffed/rebuilt all three of the interstage transformers and the metal-box capacitors for an original look.

I was able to save the original crinkle finish with just a little touch-up as well as the finish on the board. Not so lucky on the other radio, but, more on that one later -

The Masterpiece V receiver chassis. Note the chrome grid-cap shields on metal tubes. This radio has 5 bands with a range up to around 65mhz. It has 20 tubes counting the eye tube. There is a BFO designed for CW. The audio output is two 6L6s into what was the 18" Jensen, gone now but I am using two Jensen A12s like in the Masterpiece VI, and added a separate tweeter.

What is under all of those chromed shields? Better take a look if you are going to do a restoration - a lot of paper caps.

The underside of the chassis resembles a communications receiver such as a Hallicrafters.

Almost all of the original resistors were well within spec. This was a big contrast with the Strat chassis that I was working on simultaneously in which almost all of the carbon comp resistors were way out of spec.

The power/amp chassis is also chromed. Not quite as nice as the main chassis but still presentable.

Back side

The 2 Jensen A 12 speakers were not original equipment (according to mu friend Norman B.) but were included in the exchange as was the Oxford cabinet. This cabinet is most often seen with the later 15-17 model but since all cabinets were optional, any cabinet that fits is appropriate. A note that it has been reported that the Masterpiece V will not fit in cabinets made for the 15-17 without removing the chromed cover is puzzling since the chassis fits very well in this example.

The shelf was drilled for a pedestal mount speaker, probably also an A12. The front baffle is new and all 3 speakers are mounted to it.

The two Jensen A 12s have different FC DCR. One being about 250 ohms and the other being 5K ohms. This is good and similar to the FC values on the original Jensen Super Giant. An additional 50W 1K ohm resistor is placed inline with the two field coils which drops the B+ to just the right value and keeps the FCs from passing too much current and getting hot. A pair of Jensens with 800 ohm and 7 or 8K ohm field coils would be better but very hard to find and this pair is still a challenge to locate and not cheap.

I  think that the Masterpiece V is one of the best radios sold prior to WWII. Especially among those that were available to the general public (omitting some of the high tube count Scotts).

It will receive up to 65mhz, a real advantage over the Strat. This is probably a credit to the tube choices and the fact that the metal tubes were superior for RF circuits to the G type glass tubes in the Strat.

I set the 0-beat on the BFO while adjusting the IFs. It is very useful for CW signals. While the level of the BFO is not adjustable, a little careful tuning will allow SSB signals to be demodulated. This is also an option the Strat does not have.

The audio is good, really good for 1935, yet in a comparison with the 25 tube Zenith it is not quite as impressive. It does have separate bass and treble controls (tone only on the Strat) but the treble is not quite as crisp and max bass is not quite as strong as the Strat.. In this respect the 8 45 triodes with separate bass and treble interstage transformers works well for the Zenith. Keep in mind that the 18 inch Jensen would probably have helped the bass somewhat, but I am comparing apples to apples since the Zenith was stock with two A12s and a tweeter - the same configuration I am using in the MSM-V.

Tuning is always on the fast ratio until you reach the desired spot and then you can slow tune back, using the same knob. Fast and slow tuning are  separate controls or manually switched on most other radios.

There is an audio expander circuit. I'm sure it ads dome dynamic range to some music, but speech is a little weird with the volume going up and down. The expander can be switched off.

The same control will give you narrow and wide IF control. The wide IF setting would probably be used on strong broadcast stations whereas the additional 2 stages of IF selectivity are a real gain for shortwave listening.

The dial is easy to read and fairly accurate if aligned properly.

I would rather have the on of switch on either the tone or volume control but McMurdo used a separate switch mounted on the side of the cabinet.

If there is any interest, I could do a more complete comparison between the MSM V and the Zenith Strat and maybe the Scott 16 and/or the Philco 37/116 (though it is 2 year newer) and the GE M-125 (also from 1935) just for fun.

Well I couldn't wait for the tubes to get here, so I substituted some used ones in both chassis and began testing. It WORKED on the first try. Yeah, even I would not have bet on that but I'll take it.

My bench is not all that large so it take a few additional carts and such to hold all of the parts.

I did not get off with no issues though. Actually there were two.

Below you see the control/signal cable that runs between the chassis. There are three conductors that carry line voltage. Depending on the plug polarity (it is not polarized) and whether the set is on or off 120V can be on any - or 2 of the three wires. These 3 wires are twisted within the armored cable. Over years of rubbing and becoming brittle, there were many abrasions on these wires. The result could have been a short but what I saw was 120V AC on the chassis intermittently.

I knew that this cable was a problem. I had hoped that some repair to the end was going to suffice since an exact reproduction was going to be hard to produce. But now I have given into that reality.

The other issue was less significant. In the comments on the earlier Strat post below John mentioned a problem with the "Q" relay not working. Well this one - the one I rewound - didn't work either. So -

I resisted the urge to take it apart and rather measured the source voltage. It was around 300V with a short warm-up. I measured the connection to the plates of the 85 tube. It was at around 280V. So I had continuity across the relay coil and an expected voltage drop meaning that the 85 was conducting.

I then checked the grid voltage generated by the AVC tube. Something close to 0 volts allows the 85 to conduct. A signal as high as 10V will switch the 85 off, deenergising the relay. I was seeing from -.4V to about -7V. So my AVC signal was good. (when the relay is energized the closure shorts the secondary of the high frequency interstage transformer which mutes the audio until another strong signal is tuned).

So what was the issue? Checking the less than deluxe relay (see pictures in the earlier post) I found that a little nudge closed the relay. The simple solutions would be to lessen the spring tension or move the stop so that the magnetic coil was closer to the throw. I chose the latter approach and all was well.


Below is a short video after alignment. The radio is only on a short antenna so short wave reception is limited. However, when I switched on the upper band I did receive several stations, WWV and even CB transmissions. This is notable since the oscillator section of this receiver is a bit challenged above 22mhz. So I was pleased.

So this concludes the chassis restoration. Once the NIB tubes arrive (42, 5Z3 and 45s) the chassis will be reinstalled into the cabinet.

Since this project was a trade, labor less parts for a unrestored McMurdo Silver Masterpiece V, I had declined the cabinet work, instead preferring to do the fun part. The cabinet was refinished by a friend, Gary, who lives a bit north of here. The cabinet is finished, but I have only seen pictures, so far. Probably within the next two weeks you can expect to see pictures of the reassembled 1000Z.

While this project was running I was also restoring  the MPV. It is also finished - a very impressive 20 tube radio in itself. When I get some time I will post some pictures of it in the next blog.

Russ

While waiting for the arrival of the NIB replacement tubes for the Stratosphere project I have had time to work on the Atwater Kent 768Q first mentioned two posts below.

I had been lucky enough to have completed the AK 559N project a short time ago. This radio is also of that vintage with similar cabinet design as well as chassis design along with the associated common issues.

The  768Q is a 8 tube "farm" radio meaning that it was battery powered. In most circumstances, this was an effort to provide radio receivers to a large portion of the country that had yet to acquire commercial electric service in the mid 1930s.

This radio shares a cabinet with other AK models such as the AK 447. Other than the power source, significant differences between these models include  - tube count, the lack of a shadow meter and the use of a pin-type speaker using a natural magnet rather than a field coil. Most of these differences reflect the considerations that must be made to improve battery use economy. The addition of an additional tube also reflects this consideration. The 8th tube is in the audio output, the 768Q having push-pull 30s driving the speaker directly through a center tapped "magnetic" coil. This coil energizes the speaker accomplishing cone movement as compared to the voice coil in a dynamic speaker such as in the 447.

I had to use 3 separate power supplies to generate the necessary voltages. 2V for the tube filaments, 180V for the plate voltages and -22V for a C voltage (bias). I did experiment with lower plate voltages. Except for a slight decrease in volume the radio performed well down to about 135V. (decreasing the C voltage accordingly).

Above, the before and after view, noting that the cabinet had been stripped by one of the previous owners and had incurred damage including the loss of veneer as well as some structural damage.

Besides restuffing all of the capacitors and building 3 replacement resistors (note the metallic end caps of a slightly different grey/silver color) most of the rubber insulated wire was also replaced. See pile at bottom of picture above.

This chassis had survived storage very well, maybe better than any other AK of the period that I have worked on. Most of the original resistors were OK and the rubber wire was remarkably well preserved - estimating that only around 1/3 was cracked or had hardened insulation. None the less, I replaced all of the wire on the IF and RF transformers and the interstage transformer even if it appeared ok. Having the radio apart for service made replacement of the wire more practical now rather than waiting for it to fail and I did not want to take the transformers off again later. So all in all , I replace about 90% of the original rubber insulated wire with new neoprene rubber insulated wire of the same colors - or at least close.

As is often the case, the rubber insulation on the black wire was always bad and failure of other colors also tended to be similar in all examples. It seems that the pigment has something to do with the failure rate. Also degradation by mold/fungus seems to be a factor so wire that is isolated in a can or elsewhere  usually is in better shape than the mass under the chassis.

The original speaker had been removed - unplugged. It probably went to some hi-fi project, for which it would not work (well) or maybe another radio since the original owner had some interest in restoring this radio and probably had other projects as well.

Other than the cabinet being stripped/sanded, it looked like somebody had done a bit of poking around under the chassis, cutting a few wires, but nothing else.

Above: The radio in operation on the bench. Note the dial lamp. Dial lamps were often omitted from farm radios to reduce A battery consumption. It is nice that AK decided to include this option probably because it was a high end set, even for a farm radio. If the user wanted to conserve power he could have just removed the bulb.

The pin type speaker is of the same size as the original (there were two different models of speaker used in this radio). It is similar in appearance to one of the original speakers. It is not a dynamic speaker rather one that uses the lever action attached to a pin that exerts force on the cone. The "permanent" magnets are not permanent and often need repolarization. It can reproduce midrange frequencies pretty good but is very poor at reproducing low frequencies.

To make this speaker work  ,I had to remove the winding (coil) and rewind it with a center tap which goes to B+ with both ends going to the plate of one of the push-pull number 30 tubes. A number 30 is a triode similar to a 01A but with a 2 volt common cathode filament. They are efficient but don't produce a lot of audio, so using 2 in PP was a good option.

I had never noticed before that 2 of the 5 knobs have serrated edges, probably for better grip.

Above is a demonstration of the cool band selector. The 2-speed tuning is on the upper right. The knob on the lower left is a multiple position tone control and the one in the lower center is a local/distance switch.

The local distance switch is useful since it is easy to overdrive the front end increasing distortion. Testing using my AM transmitter required the switch to be in the local setting for best reproduction.

The radio has 3 SW bands with the upper band going to about 22.5 mhz. Reception on the shortwave bands is good.

The power/amp chassis is finished and while waiting for the return of the re-chromed receiver chassis I completed the restoration of the crossover network as well.

NOW the chassis is back. Really nice job on the chrome. Taking pictures of it is like taking pictures of a mirror - so forgive the reflections.

In the pictures above and below I have begun to rebuild the caps and install the new resistor kit. So the picture below is of the reinstalled new parts.

The only problem I have encountered (again) is with the small number of mounting holes that are drilled and tapped. Most of the fasteners are nut and bolt or rivets. These are not a problem. But the tapped holes must be cleaned of the new chrome and retapped. Since I prefer not to use a drill on a chrome chassis to avoid cracking or flaking the new chrome, I adapted a rat-tail file to my drill. This solution is less likely to incur those problems.

Reinstalling the parts that are riveted to the chassis is a real challenge. It takes some practice to set the rivet without cracking the fiber parts.

You just have to ignore the reflections.

Ono of the most difficult tasks in this reconstruction is the remounting of the band switch and the tuning cap.

These assemblies have a network of heavy gauge wire grounds associated with the IF section. Apparently the builders did not feel comfortable relying on chassis grounds.

Did I miss any connections?    ;-)

Trimmers and oscillator coils installed.

Moving on to rebuilding the box caps. There are 4 of these in various sizes.

While I had the boxes apart, I decided to make some replacements incase I ever needed one (pictured above).

Above is a "dry electrolytic" with a bypass resistor. From the style of resistor and cap, it appears that these might have been a factory repair since they both seem to be a year or two newer than the chassis.

Now to address the three open Candohm resistors in the center of the chassis. These are all part no. 63-407 with a value of 10K ohms rather than the values on the schematic of 10K, 5K and 5K. Since the part(s) appear to be original, I am replacing them with 10K  wire wound resistors.

There are some concerns about mounting a replacement resistor to a failed Candohm as shown above. See the video below for a solution.

I would rewind these resistors but I have not found a source for resistance wire ( nichrome or other) with values greater than about 60 ohms per foot which would require a lot of wire to get to 10K ohms.

I hid the replacement resistor for the top (stacked) Candohm below so it was far less visible - as a replacement.

Testing and alignment will begin soon.

P.S. If you find these posts interesting please LIKE or post your comments below. This is the only reason to continue posting these projects.      Thanks.

With the receiver chassis sent off to the chrome shop it's time to move on to the power/amp chassis.

Below is the sort-of before picture. Work was started on this chassis prior to my involvement. It is  shiny metal since the paint has been partially removed by wire brush. The filter caps were removed and cut open. The power/signal cable to the receiver chassis has had the connector cut off. Having done one of these before, these issues should be easy to resolve with the objective being reliable operation with an original appearance.

To repaint the chassis and parts correctly all of the iron (transformers/chokes) needs to be removed.

These are the two power transformers (large) and the two chokes.

The snap rings on the tube sockets have been removed allowing the sockets to come through the top of the chassis.

The power and signal cable going to the receiver chassis has been repaired with tape prior to being cut off of the connector. This is likely to need replacing.

OH yes! Much better.

I am going to replace parts as needed before remounting any of the iron. It is easier to work on the chassis while it is 20lbs lighter.

Replacement dog-bone resistors installed.

On this chassis these cathode resistors are 2 different sizes (watt rating). On the other chassis I restored they were all 1/2 watt.



It is time to start on the filter caps.

These were all early electrolytics. The design seems to be Sprague's attempt to copy and improve on the Mershon "wet" electrolytic can. There seems to be two or more versions used in the 1000Z. First, a solid copper can with a ground  (-) lug incorporated into the isolated base. Then an evolution to the more common aluminum can without a ground lug. The ground lug is accommodated by an additional hole drilled in to the chassis. This extra hole is seen in all of the first 254 power/amp chassis BUT may have been deleted in some of the last 100 chassis produced. The RF/receiver chassis does not have these extra ground lug holes rather using the later version mounting system.

Above: The first filter.
As you can see on the can, It is rated at 600V and 4uf.

The 600V rating poses a challenge for most electrolytic capacitors (even this one failed explosively). Knowing the compromises involved in using electrolytic caps in this position, I chose to use Solen  metalized polypropylene instead. These, too, have some disadvantages, size being the most significant. They are, however, rated at 630 volts. I have been using these in place of electrolytics in all applications where they will fit for many years now and have not had a single failure. I anticipate a much longer life as compared to electrolytic caps especially when the electrolytic caps are being operated near their upper voltage rating. An additional advantage is not having to worry about polarity (electrolytic caps are polarized). The other significant disadvantage is cost. The Solens cost about 10 times what a 450V electrolytic cap costs.

The objective in rebuilding these cans is to exceed as much as possible the original voltage rating and to STUFF as much capacity into the can as possible - within the original spec narrowed to about -10% to +150%. So, This 4uf 600V cap is now rated for 6uf 630V (tested).

The larger value filter caps are more of a problem. They have slightly less volume since they were rated for 450V. (The volume of a can is generally larger as the uf rating or the V rating increases. In these caps the 600V rating increases the size more significantly than the lower uf rating decreases it. In other words, the 4uf @ 600V can is slightly larger than the 16uf @ 450V can).


Below: the ground/lug isolation base for the early caps, showing the lead that penetrates the chassis through the 2nd hole. This configuration is not unique to early 1930s radios but this particular part with the dished edges seems unique to the 1000Z.

I did not disassemble these cap cans. I would have done it slightly differently, but, working with what I had - the replacement cap is attached to the + lug with a tapped screw treated with Never Seize (RT).

On the copper can, a ground connection is easily made to the can its self. On the Aluminum cans, I feel safest in extending a ground from within the can to the mounting hardware - not trusting an aluminum solder joint. (See picture 2 above)

To accommodate the method in which these were disassembled, the can sections are rejoined with solder. Heat must be controlled since there is a new cap inside and excessive heating will destroy it.

On the can below, I cleaned up the joint and plated the solder with copper. If this was the more common unpainted version it would be finished.

These caps were originally painted black. So the repair needs to be painted.

Do not paint the lower edge/crimp on the can. It needs to make electrical contact with the mounting hardware.

I feel, that if at all possible, the original text (value/part number) should be preserved.

The cap above is now rated for 20uf @ 630V.

Yeah, I painted my thumb too. Nice!  ;-)

With all of the parts rebuilt, tested, disassembled, painted and reassembled I was able to put the amp back together.

I have decided to rebuild the cable that links the two chassis rather than risk it shorting out.

I have accepted another Strat restoration project.

This radio belongs to Jeff, a long time local collector. He would like the chassis to remain as original in appearance as possible while still functioning like new. (Not too big of a challenge).

I believe this restoration to be critical in preserving the history of one of these iconic examples of American innovation and industrial prowess in the early years of radio. For this, I have made an exception to the "no outside projects" statement on the home page.

SO, here we go - -
This restoration may seem a little slow since I can only spend a short time over the bench on any day - getting old is a PTA, but this gives me time to accurately update this blog.

The 1000Z has 2 major chassis, The RF chassis (above) and the Power Supply/Audio Amp chassis. Additionally, the output/crossover chassis has some critical, custom, parts that must be serviced.

I have begun work on the receiver (RF) chassis and will post updates as the project progresses.

HOLD it right there - Well, after a closer examination, we have decided to replate (chrome) the receiver chassis. This is a huge amount of additional work, but it would be a shame to have the restored chassis looking like this:

Today, the documentation and removal of ALL of the components from the chassis has begun.

The dog-bone replacement resistor kit for this chassis is finished.

Updated pictures as the chassis is stripped of all parts -

Very few issues have ben found so far - which is nice.
One of the filter caps has blown the top off - will have to fix or find replacement.
The relay that enables/disables the audio in the muting circuit has an open coil (just like on mine and I suspect many others). It will be rewound.
A few of the original "paper" caps have been replaced - I will use the artwork created in the earlier restoration to build correct-looking replacements.
Chrome - as noted above.

Further deconstruction and testing reviled an issue with one of the interstage transformers.

Portion of the schematic form Nostalgia Air showing the relationship of the 2 interstage transformers
Note that two 76s drive two 42s  driving eight 45s (not shown).


Below, the deconstruction process continues.

The tube sockets are secured by a snap ring. This means that the sockets must be unwired before they can be removed from the chassis through the top.

These are the Bradley volume and tone controls. The volume control includes a section for base contour (loudness) that increases the bass level as volume decreases and decrease base as volume increases until about 3/4 volume. At this point the base boost is nil but still controllable by the tone control.

I have not seen these exact units in any other radio. It would be fair to say that replacements would be very valuable. There is no indication that these are damaged.

The trip lever on the shaft of the volume control is used to switch the radio on/off. Needing to switch 350W, I believe that a suitable combined volume on/off switch was not available.

Resistor kit for the receiver chassis below. Even though some of the original dog-bone resistors were 1/4 W the replacements are no smaller than 1W, mostly 2 & 3 W (regardless of size).

Below are pictures of the variable bandwidth IF transformers and a video showing the mechanics of their operation. Wider IF bandwidth allows the radio to detect more of  the modulation resulting in  better fidelity which is quite noticeable in the treble range. The drawback is worse adjacent channel rejection. You might also notice that a signal is slightly stronger when the IF is set to wide.

Only things left now are the tuning cap and band switch. I had left the shield on to protect the cap, but it can come off now.

The deconstruction is done. I can work on repairing the defective parts and on the power/amp chassis while the main chassis is off to the chrome shop.

Band switch and tuning cap removed.

Needed to drill out a few rivets. Above, fiber guides for the variable IF adjustment shaft. AND - NO, I didn't drill out the holes to the right. This seems to be factory. Maybe they needed to enlarge the holes after the original plating process.

Receiver chassis all ready to go off to the plater's.

QAVC relay, still needs to have the coil rewound.

Here is the QAVC relay with it's new coil.

At this point, I am going to begin work on the power/amp section and will start a new blog entry.

We had been helping sort out a collection of radios and memorabilia. Last weekend there was a sale with the proceeds to benefit OPB/Holly Theater Restoration. What is a better excuse to buy old radios than to help out a charity? Anyway it sounded good to me.

There were hundreds of items. Mostly old periodicals and the promotional trinkets and such referred to as "premiums". The sale started at 10AM which was when we got there. There were already a dozen or more people going over the tables. Since I had priced out most of the sale items there was no need  to browse. I already knew that the only things I was interested in were a little battery radio in a leatherette cabinet and a Magnavox R3 horn.

There is little information on radios sold by Wurlitzer prior to joining up with All American and Mohawk followed by the marketing of products under the name Lyric.  Since this arrangement was established in 1927 and this radio uses UV 199 tubes vintage 1923/24, it is likely to have predated Lyric.  It is still likely that it was built by All American. It is probably one of the first radios to have been sold by Wurlitzer.

In the video above the radio is driving an RCA 100B cone speaker with plenty of audio on the local stations. I was running the UV 199 filaments at about 2.9V.




The following is from a post on ARF:

Russ, it's odd that you brought this up. I've been looking into early Wurlitzer radios recently and have documented quite a few. I don't know who made your set yet, but I had a Deforest with a similar leatherette finish once. Wurlitzer had 20 stores in Chicago during the mid 20's. I'm uncertain how many stores they had in total, but it must have approached 100 or so. They advertised "coast to coast" in their ad copy. They were like the Best Buy of the 1920's and 30's and must have sold a lot of radios. They were big enough they very well might have sold different private labeled models in different regions of the country depending on what deals came along.

I have identified these mfgrs making Wurlitzer branded radios beginning about 1925:
Apex Super Five
Buckingham Radio
Mohawk Corp of Illinois

Apex was likely a one time deal due to the massive over production of the Super Five.

Buckingham never made any of their own cabinets. They made radio chassis only and promoted private label business to large retailers, dept stores, auto stores, etc so their models might be found in numerous cabinets depending on how the end customer chose to market the set. They went bankrupt in 1930. The little info I have on the early Buckingham branded sets suggests Wurlitzer made the cabinets. I am developing a history on Buckingham that I will update soon at the Radiomuseum. Buckingham's president was an interesting character. He found himself locked up overnight at the Cook County jail on two different occasions.

It's a shame Mohawk merged with Rauland because it distorts the history. Mohawk and All American should be evaluated at the time the set was made and what label it carries because these were two completely independent companies for most of their existence. I hear people calling All American sets Mohawk and vice versa which drives me nuts .

Wurlitzer sold Mohawk radios under both the Mohawk brand and also under the Wurlitzer brand. Some of the 1927-28 models were made with a completely different escutcheon plate instead of the traditional arrowhead. The knob layouts were the same. This was done no doubt to disguise them from the models being sold by Mohawk's independent dealers. Mohawk like Buckingham sold both under their own name to a dealer network and also took on private label business at least for Wurlitzer and as I've already mentioned I believe both companies relied on Wurlitzer to supply their cabinets. Mohawk made horizontal mounted exposed tube phonograph radio units for Wurlitzer and others. I'm 100% convinced Chieftan was Mohawk's attempt to dump their remaining inventory of 1st generation one-dial phonograph radio units. Chieftan was listed in one of the radio publications as being located at Diversey and the bridge. That is the exact location of where the Mohawk factory was. Alan D once argued with me that Chieftan wasn't the same, but he was wrong and I didn't know what I do today. Mohawk introduced a 6 tube "H" layout horizontal mounted exposed tube phono set that was offered in Wurlitzer's phono combo console units. This new 6 tube model would have obsoleted their old stock of phono units so I believe they made up some "Chieftan" labels and got rid of them that way. BTW, there is a Chieftan set on ebay currently. I don't want to cause any trouble with ebay sellers, but that radio has had some serious cabinet modifications.

Matt