Mercedes-Benz Forum banner

41 - 60 of 60 Posts

·
Premium Member
1967 250 SL, 1965 300SE lang
Joined
·
3,041 Posts
PM sent
 

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #42
I have been receiving several private messages from forum members who, at first, appear very eager to buy this unit, however most would-be buyers back out when it comes time to pay.

Please only message me if you intend to buy this item. My inbox size is limited to 100 private messages only. The unit is $79 + shipping and is for 6-pin DIN Becker radios. When I am out of stock, I will announce it here.

I do not currently have plans to make the 7-pin DIN adapter. I do not have a 7-pin AUX radio to experiment with and assembling these adapters by hand is too labour intensive.

Thank you!
 

·
Registered
'60 220SE - sold. '72 350SL. '81 300D. '86 190E 2.3.16V. '60 190SL - want.
Joined
·
5 Posts
any more mp3 adptrs ..

Every now and then I've been receiving messages inquiring if I have any of these mp3 adapters left. As of now, I do have a few units remaining. I will make an announcement here when I run out of adapters. Once I run out, I do not plan on making any more. I'm still trynig to get my own cost back.
8aug2013 - 1120ish pm.

hi .. saw your posting/thread on here. and saw the pics etc. I'm interested in a adpter with some 'kind of ' switch .. either push button or turn knob ..
i have 1981 300D with becker with tape and push buttons and dials.

you reply via email would be greatly appreciated. [email protected]

thank you.
 

·
Registered
1980 240D OM617.952 "Lindsay" | 1994 E320 "Lauren" | 2010 Mazda Axela "Grace"
Joined
·
541 Posts
Sorry to revive an old thread, but does anyone know where I should look to find one of these? Is there anything different between the old Becker and the new Becker? I have the old chrome Becker.
 

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #45
Do you have a 6-pin AUX connector on the back of your Becker radio? If so, I still have a few left.
 

·
Registered
1980 240D OM617.952 "Lindsay" | 1994 E320 "Lauren" | 2010 Mazda Axela "Grace"
Joined
·
541 Posts
I'll have a look at it tomorrow,many guide to removing the radio? I'll do a search
 

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #47
If it comes out anything like the Becker radio in the original post, you pull off the knobs and the faceplate and pull the radio out with your hands. There weren't any retention clips on my radio - it is held in be sheer gravity and a little friction.
 

·
Registered
1979 240D
Joined
·
949 Posts
If it comes out anything like the Becker radio in the original post, you pull off the knobs and the faceplate and pull the radio out with your hands. There weren't any retention clips on my radio - it is held in be sheer gravity and a little friction.
I just put my hand in the cassette opening and pull the radio out that way.
 

·
Premium Member
1989 560SEC AMG Euro / 2012 C300 4Matic Sport / 2006 CLS500 AMG
Joined
·
2,338 Posts
I'd be real careful doing that!

I mashed up the delicate cassette playing parts trying that once.
 

·
Registered
1984 300d
Joined
·
2 Posts
If it comes out anything like the Becker radio in the original post, you pull off the knobs and the faceplate and pull the radio out with your hands. There weren't any retention clips on my radio - it is held in be sheer gravity and a little friction.
Hello feipoa: do you have any more of the switch units that connect a cable to the 6 pin connector in the back of my Becker 599 Radio Cassette? i would be interested in buying one from you. thank you, Superman
 

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #53
The last unit has been sold. It took 2.5 years to sell 10 units. I will not being making or selling any more units. For evey 1 unit sold, I received approx. 10 inquiries (from different people).
 

·
Registered
2003 Volvo V70 5 Speed
Joined
·
1,782 Posts
If you don't plan on making or selling any more of these in the future maybe you could post the schematic for them so owners could make there own?
 

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #55
Maybe if my two screeming kids would give me 1-hr of breathing time, I would draw up a schematic, but I do not anticipate having this luxury. When I first made the units, I didn't have kids.

Don't expect to save much by making your own unit though, at least not with my design. On the other hand, if you want to copy that guys unit on eBay with just a phono jack as the switch, I think you will save quite a bit over his asking price. If I have time, I will also draw up his simple schematic and post it here. But don't hold your breath. I have a 1- and 2-year old. Need I say more?
 

·
Registered
Joined
·
12 Posts
Becker mono 6-pin DIN wiring

Folks, I want to pass along a wiring diagram and some basic audio theory, since so many are not fully informed. I am tech support manager for a pro audio company and have been working in the audio industry over 30 years, believe it if you want.

Regarding the Becker Europa MU mono radios with 6-pin DIN jacks, the commonly available aux input adapters leave a bit to be desired and in my opinion, no units I have seen are wired correctly. My diagram has all pertinent details regarding terminal identifications. Color code references, other than black and brown, are purely incidental and no standard definitions apply.

Here's the simple theory: one cannot wire two loudspeaker outputs directly together without experiencing distortion and serious loss of levels, or possibly damaging the amplifiers. Those having doubts can try connecting the red speaker terminals together on a typical home stereo or car stereo. If the rig is not damaged, some protection system should activate preventing failure. To understand the concept, realize that just because portable medial player (PMP) output is powering headphones or "ear buds" it is still a pair of loudspeaker outputs. The impedance is very low, typically less than 6 ohms. Newer designs of said players have output impedance ratings of less than 1 ohm. That being the case, the typical rule is an output should drive an input rated at 10 times or greater the source impedance. This means a 1 ohm output wants to see a minimum of 10 ohms load. If you doubt the math, just look at the specifications for headphones and ear buds. Read the wiki entry for headphones if you're interested in details, although it mentions eight times source impedance, which may pose limitations to some circuits. My device uses 33 ohms 1/4 watt resistors per channel for load, but one may be able to use as low as 6 ohms each. A source I use is a mid-1980s Walkman cassette player, which prefers a loudspeaker load greater than modern day devices.

With math and theory out of the way, I offer the low-res diagram of Becker mono radio 6-pin DIN connections. The radio has two separate "ground" terminals, whereas one is common for signal return currents and other is chassis, serving purpose of shielding wiring in cable. Do not use chassis (terminal 3) for audio return. It is a different wire given a separate purpose. Understand that Becker would not provide a separate terminal on the connector if it were not required: manufacturers do not just put an extra "something" in place for the heck of things. Cable needed requires three conductors with a shield (a k a screen) surrounding them. Four-conductor shielded is much more common, so this is what I used. The adventuresome may wish to add a 5-volt regulator and USB power connection using terminals 3 and 4. USB will only be powered when radio is turned on.

Where this all came from is simple: I prefer monaural audio in my automobile and after constructing the proper adapter, had a friend ask why his mono Becker radio (five-button Europa MU) with "iPod adapter" sounded so bad. My system got a minor upgrade along the way, with dash loudspeakers being replaced, so it performed very nicely. My buddy's system had a pair of high-end Boston Acoustic drivers in the dash, but did not sound good. This was what I started with on a mission to improve his configuration.

What I found: loudspeakers were 4 ohms each, which is low for a mono Becker. Better rating is 8 ohms per driver, since they are wired in parallel, without a front-rear fader, yielding a net 4 ohm load. I put same loudspeakers in his vehicle as I used. System immediately sounded better when playing radio. His PMP still sounded like garbage as did his phone, using an "iPod aux input" adapter "widget". I have no idea where he purchased it and do not wish to disrespect anyone attempting to supply this type of gadget for the aftermarket crowd. I took his widget apart and found the left and right signal connections wired directly together. This was the problem. After building another gadget as used in my car, with toggle switch and 1/4" jack, we tested system again. The result wast truly night and day. Maximum output level was much greater and system fidelity was significantly improved. He noticed specifically that prior setup required his player volume to be set at "7" or greater, whereas my widget yielded greater output and better fidelity with a volume setting of "5". Granted this is monaural audio, which means some bass response is sacrificed due to phase cancellation (it's just a byproduct of physics). I gave him a plug adapter for the 1/4" jack which accepts 1/8" plugs and told him once it wears out from repeated insertion cycles, just buy another one. They are less than five bucks from many vendors. It negates wearing out the widget I built him.

6-pin DIN plugs of the 240 degree variety are readily available from multiple vendors. The one I chose is Switchcraft brand, has metal body secured with screw and provides rubber strain relief. It was less than nine dollars and is made in Portugal. I will not use Chinese crap in my finely crafted German vehicle.

Final detail to know is toggle switch can be replaced with a socket having built-in switches, but the proper jack is less common and my toggle switch configuration allows selecting radio or aux input regardless of PMP cable being connected. I prefer this option.

I hope this information is useful and makes sense. Once I clean up the original image and fine tune its resolution, it will be upload along with pictures of my device.

Enjoy the music people!
 

Attachments

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #57
When I tested various resistors in the 10-50 ohm range, I did not hear any noticeable difference. It was not until around 100 ohms that I could discern the volume reduced. I do not recall what resistance I ended using in the final product. In general, the quality of sound from my Becker radio (tuner and tape) isn’t the greatest to begin with, especially compared to more modern automotive radios. Perhaps impedance optimisations are more noticeable for more radios of better quality?

I am surprised that you could discern any sound quality differences. Are you using a Becker Europa 599 like the unit shown on page 1 of this thread?
 

·
Registered
Joined
·
12 Posts
The Europa units are 5 and 6-button models "MU" (no other specific identification on chassis), as shown here: BLACK FOREST LLC - Becker Europa 5-button BC/FM Mono Radio - 1971-1980
FYI: as these radios age, bass response is reduced because output capacitors (1000 uF connected to speaker output terminal) lose value. This rolls off lower frequencies. Both radios I worked on were fully rebuilt and performing very close to "new". You may have experienced aging of the capacitor and also a very low source impedance (< 1 ohm). If the source is lower, then resistance values I list can be adjusted downward, without too much effect. 1:10 rule should be followed. As a side-note, it is worth noting that a lower impedance demands more current, thus battery life from player will be lessened. Granted it is theoretical, but physics still apply. I will also mention, being an audio professional, I pulled out signal generators and a real-time frequency analyzer to verify we were not just "thinking it sounded better". Testing proved the series load resistors improved performance.
 

·
Registered
1979 240D
Joined
·
38 Posts
Discussion Starter #59
What aspect of the speaker output capacitor is causing reduced bass - the ESR or the capacitance itself? Is it only the low frequencies that fade? What about the higher frequencies? I do not find the treble to be all that impressive either. I don't recall hearing any human audio able difference between 0-ohm and 10-ohm series resistances. What can I do to improve the sound quality of my old Becker?

If I hook my oscilloscope up to the speaker output of my radio what should I be looking at to verify that series resistances show any sound quality improvement? Is it that I am to take the FFT of the signal and look for increased amplitudes of the signal in the frequency domain?

Thanks.
 

·
Registered
78/82 300D
Joined
·
5,180 Posts
Here's the simple theory: one cannot wire two loudspeaker outputs directly together without experiencing distortion and serious loss of levels, or possibly damaging the amplifiers.

Those having doubts can try connecting the red speaker terminals together on a typical home stereo or car stereo. If the rig is not damaged, some protection system should activate preventing failure.
OKAY OKAY....

I am not getting all this....are you saying you are not suppose to wire two speakers off of one channel??

I just had to stop in....and "clear up" a few things....I don't doubt your 30 years of experience though I could say I too have that experience as I worked in best buy for 30 years..J/K

I have been working on audio equipment, researching and reading period books....going all the way back to crystal and battery sets....we are talking EARLY audio...

No offense but 30 years in the field means you came into being as transistorized technology has gotten cheap and Chinese.

One cannot make these theories on audio unless they know the basic principles of audio, how it is made and certain equipment...

You never got into the guts of the radio, never opted to look for original service manuals, bulletins and schematics...or SAMS...

You simply discovered the DIN port on the rear of the radio that was added for option equipment such as uber rare cb radio...if anyone just googles around they will find it...such as they did on ebay..

Not saying anything bad about your adapter...just saying it was/is pretty much a copy of a of a connecter that has been able to be made for god since the 30's....German electronics and audio is far superior to anything produced around here at any time..

The whole ohm debate doesn't mean squat....its like these people who "assume" they need a 2500 watt 8ohm system for good audio...I was producing concert quality audio with as little as 6 watt and 16ohm...

Before one starts giving theories. I want these people to actually study the design or the radio they are attempting to mod.

You just can't go and install any modern day speakers in these cars as they are not matched to the impedance of the radio. One needs to look at the specifications of ones radio and then buy compatible speakers.

You may have experienced aging of the capacitor and also a very low source impedance (< 1 ohm).
This member brings up a very good point. Capacitors age and the shelf life of a capacitor is typically 15 years. If the units aren't used, abused etc they fail faster.

I have personally looked into the costs of rebuilding these radios for clients or selling refurbished units. It is very VERY hard to find a good cores as car radio's don't age well with heat, abuse and stress.

Before one can even begin to make an universal adapter(impossible) one needs to start with a solid plat forum. That is a restored radio with all new capacitors, cleaned and lubed controls, fresh solder etc. They should also be scoped and compared to original schematics.

The only fail way to make a universe adapter is from the cassette head but this requires a mod to fool the radio into switching to cassette mode.

I highly urge people to not use this din port for audio/power input/output until you read what was original outputted from this port. AKA this radio was never built solidly enough to be adding external do dads to it. The option accessories of the time were constructed through many many many years and very well experienced technicians, doctors and engineers.

Becker roots can even go back into WWII and Hitler....if you have studied audio for as long as I have.

I have a spare becker outside that I can open and show the guts off and show why these shouldn't be moded with out actually electric/audio engineers.

There is a reason Becker AutoSound LLC - Mercedes BMW Ferrari Porsche Auto Audio Repairs charges so much for restoration and mp3 adapter install.

If people want good 1/4 jack input for this radios. Use a cassette adapter. Granted alot may have the cassette mechanisms with broken belts etc but on both of mine becker and blaupunkt(amazing audio) all I needed to do was to clean the cassette head with rubbing alcohol and qtips..ALOT of qtips.

FYI if you don't have one of these in your basement you do not need to be working on anything audio related.


Electronics and Antique Radio Workbench Basics
 
41 - 60 of 60 Posts
Top