The old Melos - CB conversion help required

[JLow75]

I have an old, very tidy MELOS DE-1 echo &, whilst I don't use CB much anymore, I would like to convert it to use with my Uniace 200 a blast from the past on 19!

I am a 20 year time-served electrical/electronics technician & bench fitter I get bored on my dinner breaks & like to mess around with such projects nown and again as I have access to all componenets, tools & equipment etc.

I have looked on the net & found no actual specific 'guide' - has anyone got one on here?, or could help me out with a few things.

I already know about changing the 50K delay pot for a 220K for the 'extended delay'.

Off the top of my head, this was how I was going to do it.

1. I was going to remove the 6.3mm audio 'Mic in' socket & mount a 4-pin standard Mic socket in it's place (or mount one on the side of the housing) & wire the MELOS input wire to Pin2 of the CB mic socket & the common to Pin1

2. Remove the 6.3mm output audio socket from the MELOS & replace it with a 6.3mm stereo socket to gain an extra 'pole' to use for TX then take the TX wire straight from Pin3 of the new socket Mic socket to the now extra pole on the output socket

Make up a 6.3mm male to 4-pin mic plug 'adaptor' lead - which should have now an output audio / TX & common

Would that work? - or are there any modifications to do on the board? - for instance I would be using a standard coffin mike - is the impedance suitable for the MELOS input? - I don't want to blow anything up!

I was considering using a standard audio mic & fitting a 'switch' on the front of the MELOS to key-up but I don't fancy that idea.

Anything untoward with my method, or any other information would be gratefull.

Thanks in advance

[163TM847]

The one i have has a four pin socket on the front, And a cable coming out the foot switch socket on the back with a four pin plug on it.

The cable is just four wires [3 coloured and a braid]

The braid is connected directly to the input mic socket and back too ground on the main board, The RX and TX wires are also connected directly to the input mic socket, The TX audio wire is the one you need to put "inbetween" the input and the output.

If your stuck i can easily take mine apart if you want to

Yes this is the one that was listed on Ebay recently, It wasnt mine at the time and the owner wanted too much for it so i ended it early, It's mine now and will probably be relisted soon.

[bigpimp347]

the way i do mine when i do..
socket on front.
cable out the rear
solder cable to the socket like an extension.
the depending what radio it's for..
remove the wire from the socket thats the audio..
take a wire from the socket yo the MIC in hot side of the melos socket.
the the audio wire in the cable connect to the audio/line out of the melos.
i also connect the earth of the socket to the earth of the line in and out.
and if there's any hum or buzz a small cap across audio in and audio out to earth.

done this on a few..
usually where the mini coax cables are on the melos board is a good place for wires.
or direct to the volume on the control is another.

[Oggy]

Not that i'm into echo boxes , but I do own a Melos DE1, mine has had the socket conversion, in the same way the one I sold in 1985 had too.
the tidyer way would be to use the plugs on the front with special bespoke leads.
But all it will do is cause your audio to sound hard to understand.......better off building a speech prossesor box from Spectrum communications and enhancing you audio, now that would be a nice little project for you

[Admiral]

Further reading if you haven't already.

http://www.transmission1.co.uk/forum/vi ... =2&t=20980

[Oggy]

Not that I'm into "Beat Box" by middle aged blokes

But this is the same as mine http://www.youtube.com/watch?v=bwtpvD4Y4YM

[JLow75]

Thanks for that, yep got it.

it will probably go on eBay when I've finished it & make a triple profit

Yes I will put a cable out the back, rather than utilise the front socket.

and the adaptor lead I make up for my Uniden radio I take it I can just link in the plug pin 4 to the common for RX?

I thought I had one, but can't find it - where can I buy a standard 4 pin mic chassis mount socket? cheap.



Cheers

[JLow75]

As long as you don't go OTT with the depth/repeat & delay & set each one to the right amount, working with each other, I think you can tailor the MELOS sound to be quite nice & perfectly acceptable

[The Collector]

Thread resurrection time -

I have just bought an analogue Melos DE1 with a 4-pin CB socket mod and although I can adjust the outgoing audio with the volume knob, none of the other 3 knobs make any difference at all. The balance knob turns the volume down at nearly max setting.

I'd assume that the wiring is correct as RX/TX and incoming and outgoing audio all work, it's just that there's no echo.

Could the internals somehow have been wired up wrong allowing only the volume/gain to work, or do you think there's basically a fault? Looking inside it, there's no real sign of loose wires, bad soldering etc.

One thought from my non-educated mind, the wire from the inside of the jack plug socket goes to pad no.2 on the circuit board as mentioned above, but the wire from the back of the 4-pin mic' socket (I assume the outgoing audio wire) goes to solder pad no.1. Wouldn't they go to the same pad?

The sellers says it worked fine with a stage mic' plugged into it, so I'm suspecting it may be wired wrong...hopefully.

Any ideas please???...

[lambrettadave]

Maybe a modern condenser microphone might make it work.

Not to sure on your model but I can remember a friend buying one years ago and it needed a new tape in ite.

[The Collector]

Maybe a modern condenser microphone might make it work.

Not to sure on your model but I can remember a friend buying one years ago and it needed a new tape in ite.

It's the newer non-tape black-fronted version Dave.

I've used them in the past without an issue with mic' types and my Echotek MX-99 works fine with normal/power mic too.

I'm hoping someone will say it's a simple wiring issue.

The links to the pictures above have long gone which is a shame as that may have helped a technophobe like me suss it out.

I can add some pictures if anyone in the know thinks it'll help. The seller said it was okay to open it up and have a look inside in case it's something that's easily fixable, save sending it back. It'd be awkward if it did go back and was then found to work fine with a guitar and amp (and no, I don't know anyone with those to try it on I'm afraid).

[lambrettadave]

I would pm to Dave m0ogy and see if he can help you out with photos.....

[The Collector]

I'll take a few pic's when I go up in the loft later and see if that clarifies anything I've tried (probably badly) to explain

[The Collector]

Pic's:

[The Collector]

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