Oval Era Motorola Radios

[flyertim]

Oval Era Motorola Radios

I spent several months last winter restoring and researching the original Motorola 8M radio from my 1957 beetle. Now that I’m finally finished, I thought I’d post my findings in a thread dedicated to the oval era motorola radios.

There were many questions that popped up while restoring my radio. For example, why were all us spec beetles delivered to the United States without a radio? What radios were installed into oval beetles? Why are they called “Big M” radios? I hope to answer these and other questions about our Motorola radios.

For the research portions of this essay, I will write in a modified MLA format as that’s how i was taught. For those of you not familiar with MLA, any citations will end with the authors name in parenthesis and the supporting documentation will be provided in the “works cited” section at the end of every post. Anyone wishing to delve deeper into the subject can look up my resources.

As always, input from members of the samba is not only welcomed, but encouraged! So have a seat, grab your favorite beverage and prepare yourself to learn more than you’ve ever wanted to know about the Motorola “Big M” radio.
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

So, why were US-spec Volkswagens imported without radios? Why didn’t my car come with a Blaupunkt or a Telefunken radio? Eric&Barb mentions that “it was illegal to import “Brand NEW” autos with radios in them from abroad” (kafer53). I didn’t understand how a radio could be illegal. If it’s illegal, wouldn’t there have to be a law written somewhere?

After many searches on the internet, i came across a forum for antique ham radios. I found out radios can be considered illegal if they break the FCC’s rules and regulations.

In one thread KC2LNB asked “…what is considered a[n] illegal radio?” Several posts mention that there aren’t illegal radios, just operators who use radios illegally. One example mentioned by WA9SVD is that an older radio “can receive cell phone frequencies” (KC2LNB). Therefore, one can eavesdrop on cell phone conversations, which is certainly illegal without a court order. It wouldn’t necessarily be illegal to own such a radio, but it would be illegal to use it for eavesdropping.

Now, let’s take a look at a Blaupunkt radio.

Sunroof53 explains what the LMKUU buttons stand for:

[“L”] Langwelle (long wave)
[“M”] Mediumwelle (medium wave)
[“K”] Kurzwelle (short wave)
[“U”] 2 x Ultrakurzwelle (ultra-short wave or very high frequency) (vanagon91)

In the US, AM radios operate in the 520-1640 Khz frequencies. This is equivalent to the “M” range on the Blaupunkt. As you can see, the Blaupunkt radio can pick up more than AM radio stations. In Europe, the L (long wave) band is used “for commercial broadcasts, however in the US, the L band is used for aviation and weather broadcasts”. (White) As a result, this radio would not have met the FCC’s rules and regulations and would not have been allowed to be imported into the US.

So, European radios would not have been imported into our oval window beetles because of the frequencies they can receive.

Works Cited

kafer53. “Question on Motorola “Big M” Radio.” 17 Oct. 2005. TheSamba.com. 11 April 2012.
<www.thesamba.com/vw/forum/viewtopic.php?t=138509>

KC2LNB. “What Do You Call a (sic) “Illegal” Radio?”16 Oct. 2007. QRZ.com. 11 April 2012.
<http://forums.qrz.com/showthread.php?140540>

Vanagon91. “Blaupunkt Frankfort Buttons Mean” 22 Oct. 2010. TheSamba.com. 14 April 2012.
<www.thesamba.com/vw/forum/viewtopic.php?t=437203>

White,Charlie. “Blaupunkt Radios for 356 Porsches.” 1 Jan. 2012. DerWhite’s Blaupunkt Radios. 21 April 2012.
<http://derwhites356literature.com/DerWhitesBlaupunktRadios.html>
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

Since radios were not installed into Volkswagens destined for the United States, what radios were installed into our oval beetles and by whom? Several threads here on the samba mention that radios were installed by the dealer. I found a thread in the Porsche 356 registry which states that radios installed into Porsche 356’s were “installed by the dealer at the time of sale and sometimes months/years after the sale” (Poulikakos). Even “MGs (and all British cars) were delivered to the USA without radios, leaving it for the customer to choose which model and the dealer to install” (Paul).

So, why did Volkswagen dealers chose Motorola over other American radio manufacturers? The answer is simply because Motorola offered a universal kit that fits into the ’53-’57 beetle dashboards.

For example, the photo below is a scan from a model 6M installation manual available in the samba archives. The scan shows this is the owners guide for installing kit #AK-158 specifically into 1953-1956 beetles.

Works Cited

Paul, Jim. “MGA Radio.” Web. 21 April 2012.
<www.jimpaul.tv/mga/mods3.htm>

Poulikakos, Peter. “Radio Identification.” 14 April 2008. Porsche356registry.com. 21 April 2012.
<http://porsche356registry.org/356talk/1/12555.html>
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

There are only four Motorola models that are considered “Big M” radios. They are the 5M, the 6M, the 7M and the 8M. The model number of the “Big M” corresponds to the year in which they were introduced. For example, the 8M is “new” for the 1958 model year. However, it was available in the latter half of 1957. This follows the “model year” manufacture of automobiles.

Here’s what you need to look for. Almost every radio I see in the classifieds fails to show a picture of the right side of the chassis. This is where the model number is stamped.

Why are these radios referred to as “Big M” radios? By the large “M” logo on the faceplate of course!

This logo was “created by award-winning graphic designer Morton Goldsholl in late 1954” (Motorola). It’s still in use today.

The previous logo was a squiggly line (or, maybe a sine wave) as seen here:

The faceplate at the top of the image belongs to Dlux55 who mentions that this faceplate “came in my Jan. 1955 beetle…radio is 5M” (coad). The radio below the faceplate shows the same squiggly line logo. Since the 5M radio would have been available in late 1954, this faceplate may have been used before the new logo was introduced.


Works Cited

Coad. “Big M Radio Question.” 18 Feb 2005. TheSamba.com. 21 April 2012.
<http://www.thesamba.com/vw/forum/viewtopic.php?t=102699>

“Motorola.” Wikipedia. The Free Encyclopedia. Wikimedia Foundation, Inc. 14 April 2012. Web. 21 April 2012.
<http://en.wikipedia.org/wiki/Motorola>
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

Model Number Differences

You will notice that all four versions of the “Big M” radio are identical in size and appearance.

Aside from the model number stamped on the right side of the chassis, the only visible difference between the 5M, 6M, 7M and 8M radios are the knobs.


5M knobs:

…which are available as reproductions from Gary at Brezelwerks:

www.thesamba.com/vw/classifieds/detail.php?id=322749


6M knobs:

In the photo below, the knob on the left is correct for both the 7M and 8M radio. The one on the right belongs on the 6M.

7M and 8M knobs:

These knobs are also available (in ivory or black) from Brezelwerks:

www.thesamba.com/vw/classifieds/detail.php?id=529863
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

The 5M Radio

Here’s a vintage picture of the Motorola 5M radio taken from the SAMS photofact (more on these later):

The 5M radio was also available in a 12-volt model. The model number is 5M-12.

Here’s several pictures of a 5M radio:

This is another 5M radio, with the correct, original knobs…before restoration:

The 5M radio comes with a cloth covered power wire and fuse holder as seen below.

In this picture, extra cloth wire is seen to the left (along with some brown cloth wire), which is a perfect match for the original. Seen above the wire is a new inline fuse holder which also matches the original perfectly.

I purchased the cloth-covered wire from Sundial Wire:

http://www.sundialwire.com

The inline fuse was purchased from Electronics Plus. The part number
is FHP1.

http://www.electronicplus.com


Original speaker wires:

The original black “bullet style” knobs…

“Before” pictures continued…the chrome faceplate removed:

The top cover removed to reveal the internal electronics:

The bottom electronics:

here’s the 5M after restoration:

Also unique to the 5M radio is the glass dial scale. It has a different font vs. later (6M, 7M and 8M) radios as seen below:

The 5M dial scale is on top, the later dial scale is beneath it. On the 5M, the “Motorola” font is block lettering and “Volumatic” is italicized. On the later dial scales, “Motorola” is italicized (along with the font change) and “Volumatic” is not italicized.
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

The 6M Radio

The 6M radio from the SAMS photofact:

The 6M radio was also available in a 12-volt version…the 6M-12.

Here’s a few examples of 6M radios:

Remember, the 5M and the 6M radios were both offered in 12-volt versions. Here’s an example of a 6M-12…

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

The 7M Radio

Here’s the illustration from the SAMS photofact:

The 7M radio was only available in 6-volts.

Here are photos of the 7M radio:

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

The 8M Radio

The illustration from the SAMS photofact:

The 7M and 8M were identical except for some electronics updates. The 8M was only available in 6-volts.

Here’s an unusual 8M radio…it has original ivory knobs. Most knobs were black.

My 8M restoration

The following post is a “copy and paste” from pages 19-21 of the build thread for my ’57 beetle. The link can be found in my signature.

the photo below shows the dashboard of my beetle soon after it was pulled out of the barn. notice the car has the original motorola “big m” radio.

here’s the radio pulled out of the car. the stamping on the right side of the chassis tells us it’s a motorola 8m radio. the “149514” might be a serial number (???) and the “25” could be an inspector’s stamp(???).

here’s the front…

closeup of the front. note the bracket to the left has an “L” stamped into it (red arrow) which will be helpful for reassembly.

the left side…

the back…

the top…

and the bottom.

i posted these photos for reference.

the radio doesn’t look too bad. it just needs a little tlc!
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

after reading several threads on the samba, i decided to send the radio to mr. wilford wilkes to see if could be brought back to life. also, since he lives in pennsylvania, i figured shipping would be quicker and cheaper to and from ohio.

here’s his contact information:

Mr. Wilford Wilkes Sr.
Vintage European Radio Repair & Sales
Vintage Radio Shop
170 Opossum Alley
Brisbin, PA 16620

(814) 378-8526

i called him first to give him a heads up as well as shipping instructions.

a few days passed when i received a call from mr. wilkes. he said the radio looked pretty good. he estimated the cost to be around $200 to repair.

i gave him the go-ahead and asked if he could also straighten out the tuning shaft (the one on the right) as i noticed it was a little bent. he said that he would give it a try, but they are pretty fragile and usually snap off.

a week later mr. wilkes called to say it was finished. he replaced the vibrator and a few vacuum tubes and a couple other little bits. the good news was that it worked!

here’s a picture of the radio when i received it back in the mail.

i had also asked mr. wilkes if he could do a cosmetic restoration. i wasn’t sure what to expect and actually, i was a little disappointed with what i received. the silver paint was thick and had runs in it…and the black paint on the dial plate was obviously sprayed over the surface rust.

i hooked it up to a 6-volt car battery and after a few crackles, pops and puffs of ozone, it worked just fine. so, i was happy about that.

also…i’m not trying to diss mr. wilkes work. i don’t believe he offers full restoration services, so i was asking for too much…he did what he could and he got it running.


here’s a view of the back of the radio.

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

i spent several weeks contemplating what to do with the radio.

basically, i was afraid to take it apart. what if i messed something up and i would have to send it back to get repaired yet again? a radio delete panel is less expensive than the $200 i had already spent to get this thing up and running.

since the radio would be visible from inside the trunk (unless i can find a suitable wiring cover), i decided to just go ahead and take it apart to see what i can do.

first, i took off the top cover.

there was a lot of caked-on, oily dirt over everything from the years gone by.

i grabbed a bunch of q-tips and rubbing alcohol. i cleaned as much as i could.

much better…

i really wasn’t happy with the silver paint. the chassis looked like it was originally zinc-plated…if i bead-blasted it, i would remove the coating. chemical stripping would remove the paint, but not the surface rust.

when i took the top and bottom frames off the main chassis, i noticed several electrical parts were grounded by being soldered directly to the chassis. we’re a little spoiled nowadays…can’t just remove a pcb board!

so there was no way i could remove all the parts, have the chassis replated, reassemble everything and actually have it work!

i decided to just go ahead and bead-blast the radio. i was really nervous about this because of all of the holes…i was worried about glass beads getting inside and screwing things up.

so, i taped all of the sides from the inside with masking tape and shoved tissue paper into all the nooks and crannies, then masked the top and bottom…then i hoped for the best.

here’s the bottom taped up.

by the way, i removed the front dial plate before blasting, but i don’t have any pictures of this.

i used low air pressure and glass beads to just carefully “frost” the chassis. when i was finished, i removed the tape and tissue. i was happy that the glass beads didn’t find their way inside.

i hooked it up to the battery to make sure it still worked…it did, thank goodness!

after bead-blasting, i thought the raw metal looked pretty good. rather than paint it with a silver color that’s close to zinc, i sprayed some gloss clear on it.

it’s a little darker over original, but looks pretty good in person.
_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

here’s a picture of the radio ready for reassembly after the bead-blasting and clear-coat.

…and here’s the back.

a nice view of the bottom electronics.

another reference shot of the electronics from the top in natural daylight…

the top and bottom frames have been bead-blasted and clear-coated.

the next picture shows the top and bottom frames installed onto the chassis with new #6 x .25” self-tapping screws (these screws will be used throughout the reassembly process).

here’s a view of the back.

the green arrow points to the original ¼”-20 x ½” bolt and ¼” star washer that holds the support bracket…both of which have been bead-blasted and clear-coated.

the red arrow points to the new speaker wire i installed. i found a local antique radio supplier who had this wire. it was “scrap” to him, so he just gave it to me…score! since the original wire was too short (must have been cut sometime in the past) and the solder joints were easy to get to, i figured new wire would look better than a splice.

back to the front, i’m ready to install a new bulb into the socket.

notice this isn’t an incandescent bulb, rather an led bulb that’s available from “my59vw” in the classifieds:

http://www.thesamba.com/vw/classifieds/detail.php?id=1260565

also, they are available in different colors…i chose amber.

next i installed the bracket that holds the dial plate in place (red arrow). it was bead-blasted and clear-coated, then installed with new #6 screws (white arrows).

the led bulb and holder slides onto the bracket from the left (yellow arrow).

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

let’s turn our attention to the dial plate assembly.

this photograph shows the dial plate (not sure what it’s called, so i’ll refer to it as the dial plate) which has been bead-blasted and painted gloss black.

the next piece i need to install is the tuning shaft.

now, before we go any further, we need to take a few steps back.

the photo below shows the front of the radio when i first received it from mr. wilkes. as mentioned previously, i knew the tuning shaft was bent. when mr. wilkes called me before shipping it back, he informed me that the shaft did indeed break. he tried to straighten it as best as he could, then he crimped a sleeve onto it (the blue arrow points to it).

initially, i didn’t mind…as long as it worked, but when i installed the knobs, i couldn’t help thinking i was looking at marty feldman as i turned the knob.

so i removed the shaft to see if i could fix it.

i removed the sleeve mr. wilkes installed and tried to reattach the broken end by drilling and adding a pin…then silver-soldering the pieces back together. this didn’t work as well as i had hoped.

also, the shaft was actually bent in the area where the dial cord attaches. i tried to straighten it, but nothing i did seemed to work.

here’s the bent and broken shaft:

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

i searched the classifieds as well as the internet for a parts radio. i found a couple, but the shafts were missing or bent…seems like a common problem.

so, i took the sad remains of the original tuning shaft, reversed-engineered it and drew it in solidworks.

it looks like i will need to make another one from scratch.

i decided to make the new shaft stronger than the original. so i chucked up a ½” diameter piece of titanium rod into the lathe.

i used gibbscam to write the g-code (language the cnc lathe understands) from my solidworks model.

the photo below shows the lathe in action as it makes the final pass on the titanium.

the outer contours are done. a parting tool will be used to remove the shaft from the stock after measuring to ensure accuracy. (everything was perfect to .001”…damn, i’m good!)

here’s the part after cutting it from the stock.

next i need to drill a ¼” diameter hole about 3/8” deep into the aft end.

i turned a piece of delrin on the lathe to safely hold the part while i drill the hole. i drilled a 5/16” hole through the center, then i used a saw to cut a slit into the delrin.

when i clamp down on the delrin, the gap closes up so it grips the part without leaving any marks. (makes sense?)

the parting tool usually leaves a little bit of material as the part is cut from the stock…so this needs to be removed first.

in the photo below, the assembly is chucked up into the lathe. the red arrow points to the delrin. the cut i made with the saw is also visible. the blue arrow points to the 35° cutter i will use to face off the end of the part to remove the extra material.

the end of the shaft has been faced off. a center drill is mounted into the tailstock to use as a starter bit which will give me an accurate starter hole for the ¼” drill.

the starter hole is finished and the ¼” drill bit is mounted into the tailstock. i only need to drill about 3/8” deep.

all work on the lathe is finished!

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[wayne1230cars]

A very interesting and informative post. Well done!
_________________
1960 beetle
1970 beetle convertible

[flyertim]

here’s another solidworks screenshot. i designed a fixture to hold the shaft while i drill two .046” diameter holes for the dial cord to pass through.

i will make the block out of another piece of delrin…this is the transparent rectangle in the screenshot below. two vertical shafts can be seen in the fixture just above the holes in the barrel of the shaft. these will act as drill guides for the tiny 3/64” drill bit.

the fixture with the shaft is mounted into the vise on the mill. you can see the 3/64” drill bit mounted in the tool holder. i drilled through the delrin and the titanium as a set.

i was really afraid of breaking the drill. i used a straight-flute cobalt drill bit and hoped for the best. i kept the feed rate slow and pecked .005” at a time. also, you can see i flooded the parts with cutting oil to keep things cool and lubricated.

success! and i didn’t even break the drill!

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

next i made the slot on the aft end. i used a keyway cutter to do this which can be seen in the photo below. once again, .005” a pass…nice and slow.

a slot needs to be cut into the other end as well. another fixture was made from delrin, then the slot was cut.

the finished part (sorry it’s blurry…gotta work on my depth of field photography…) which is alongside the original shaft.

by the way…to answer your question…yes, it’s super light!

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

back to the assembly…

i placed the new titanium shaft into the hole on the far right of the dial plate which is held in place with the original circlip.

after several searches on the internet for the string that operates the indicator needle, “vintage radio dial cord” got me where i needed to be. i found a supplier that had a spool of 25’ x .028 diameter dial cord for $4.00. i measured the original dial cord which was about .025 diameter, so this should work okay.

i read a few vintage radio forums and beeswax is recommended to coat the dial cord for smooth operation. a plastic container with beeswax can also be seen in the photo below.

i cut a piece of cord about 12” long and threaded up, through and down the holes of the shaft.

i purchased the sams photofacts schematic for the 8M radio. i sent the jpegs to everett who posted them in the technical/owner’s manuals/technical instruction manuals/radios section of the samba:

http://www.thesamba.com/vw/archives/manuals/big_m.php

let’s have a look at the second page…

notice the illustration in the lower right-hand corner that the dial cord is wrapped around the shaft 8 ½ times. it also shows how the dial cord is looped around the pins.

it was impossible for me to take pictures of the cord being installed as there was too much going on.

so…in the photo below, i have wrapped the cord around the shaft clockwise (the part of the cord from the hole closest to the dial plate) 8 ½ times. then i looped it around the pins in the dial plate as seen in the sams photofact illustration.

i dipped a toothpick into superglue to secure the knot.

here’s a better picture of the dial cord installed.

if i use my thumb to straighten the shaft in the dial plate, notice the dial cord is nice and tight.

the red arrow points to the slot in the tuning shaft. although it’s vertical in the photo below, i made sure it was horizontal when the knot (yellow arrow) was all the way to the right (green arrow). you’ll see why in a minute…

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

i went to the hobby store and found fluorescent red paint which was a perfect match for the original indicator needle. after mixing the paint, i used tweezers to hold the part and i just dipped the needle into the paint. i left the patina on the rest of the part since it isn’t visible.

i slid the indicator into the dial plate and pushed the dial cord between the tangs.

i didn’t crimp it yet…

i’m not sure what to call this piece…the radio dial? [edit: it’s called the glass dial scale] fortunately, it’s made from glass…not plastic like today’s crap. so it cleaned up real nice!

it’s held in place with these two clips.

the glass radio scale is installed onto the dial plate.

notice the indicator needle is right above the adjustment dot in the photo above. if we go back to page 1 of the sams schematic, there’s alignment instructions.

“pointer adjustment: set radio to high frequency end stop. slide pointer so that it coincides with calibration dot at extreme right. cement pointer to dial cord.”

In the photo below, i installed the dial plate assembly onto the radio. the hole on the far left (hidden by my hand) slides over the power/on/off shaft.

notice the indicator is still to the far right of the dial (red arrow). the slot in the tuning shaft (white arrow) needs to align with the cross pin in the other half of the tuning shaft that’s attached to the radio (green arrow).

i turned the stub shaft (the part in the radio) clockwise until it stopped. this made the cross pin horizontal. if you recall, when i installed the dial cord, i made sure the slot in my new titanium shaft was horizontal when the knot was at the far end of it’s travel.

hopefully this makes sense.

the dial plate is held onto the bracket with the same #6 self-tapping screws as before (red arrows).

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883

[flyertim]

the next parts to install are the two brackets that mount the radio to the dashboard as well as mounting the chrome “big m” faceplate. they have been bead-blasted and clear-coated. also, remember the left bracket has an “L” stamped on it…so i put it on the left side.

by the way, i have seen some radios with an “R” on the right bracket. however, it isn’t on mine.

they are held in place with #6 screws.

here’s my original “big m” faceplate and screws…

…and here are the parts after rechroming. also note two washers which belong under the faceplate and outside the metal dashboard.

if you look at this picture, which is also available in the radio section of the technical archives, you can see where these washers go. look for the trimplate on the right.

the chrome faceplate installed onto the radio…

_________________
"Broadsword calling Dannyboy"

my '57 rebuild:
http://www.thesamba.com/vw/forum/viewtopic.php?t=369883