magnum 257 microphone-how does it work?

[space cowboy]

more specifically, the channel buttons on the mic.
While I like the radio, I hate the mic. Tiny, short tight cord, power adjustment inside the microphone...:glare:
While I have my road devil wired for it, the radio is across the car and channel buttons on the mic are a nice feature.
The astatic has 6 wires, I see no reason why I can't use one of the 2 extras to pin 4 and some custom installed buttons.
I've read one switch needs a 22k resistor and the other a direct connection, but the question is where do the backsides of the switches connect to? I've seen pin 3-transmit, is this true?
there also seems to be some disagreement as to whether the resistor is for going up or down...
anyone do this already?

 

[9C1Driver]

The stock Magnum mic is a power mic and works great. I suppose you could have a long stretch cord installed I guess.

Doug at Custom CB Radio can wire up down buttons for any mic if you want.

 

[BBB]

You can also get a special Magnum 257 2018 Extreme Echo power mic that is wired from the factory so you don't need a 9 volt battery. I have one and they have excellent audio, add echo to a rig that would otherwise not have it and you never need to change the batteries.

I'm not sure how many conductors the mic has in the cable to add switches. It is quite chunky and appears to have plenty of room to add the switches if need be.

Another option would be to find an RCI/ Ranger SRA 158 mic that already has the channel buttons on it. It is not a power mic but does have some decent audio.

Here's one: RCI Ranger CB Ham Radio Replacement Mic Channel 6 Pin | eBay

Be careful rewiring the mic plug as one of the pins on the 257 radio's mic jack is hot VDC.

 

[space cowboy]

thanks for stopping by guys, but...
I know the stock mic is a power mic 9c1, and it does sound decent, but even a new cord won't fix the too small and internal adjustment issues. besides, the RD104 is well suited for my voice and I like the noise canceling. I've actually had people disbelieve that i was a mobile with it. I'm arguing with these guys whether or not I'm a base while driving 45 down the road with the window down. it's hilarious. there have even been some that wouldn't believe me, with witnesses, until they came out and saw for themselves.
As for Doug at custom CB-it's always good to get a good report on a CB shop, they're disappearing so it's good to keep an eye out, but then it wouldn't be my project, plus it would cost quite a bit more than the 3$-4$ I plan on paying for the switches, and going to the post office isn't quite as satisfying as putting it together myself.

I've read several things that state NOT to use ranger mics on magnum 257 radios BBB, that it will fry the radio because they use a different method of channel changing that aren't compatible.
the 2018 mic looks interesting, thanks for letting me know about it, but not really in line with what I'm doing.
all I want to do is install buttons on my RD, I'm not looking for any more new equipment at this point.

 

[9C1Driver]

That is correct, an RCI 6 pin will have to be re-wired to work on a Magnum radio. There might be a mod project over at cb tricks on adding up down buttons to RCI and Magnum mic's.

 

[2RT307]

Seems like the Road Devil would be do-able. I've seen 636L's with channel buttons added, and the RD is the same housing.

73,
RT307

 

[jazzsinger]

according to this schematic,

http://www.cbtricks.com/radios/rflimited/magnum_257/graphics/magnum_257_sch.pdf


the up button takes its power from pin 3 (tx) via a 22k resistor, then goes to pin 4,the dn button goes also from pin 4 and is grounded via pin 5.

shouldn't be too difficult to add your own buttons and use any spare wires not used in the mic cord, if there isn't enough wires in the mic cord then replacing it would be the answer.

hope that helps as i'm not too familiar with magnum radios.

 

[Turbo T]

You can also get a special Magnum 257 2018 Extreme Echo power mic that is wired from the factory so you don't need a 9 volt battery. I have one and they have excellent audio, add echo to a rig that would otherwise not have it and you never need to change the batteries.

Does this "special" 2018 not have the batt compartment? Or is it the same as all the other oens you see on ebay and everywhere else?

 

[Mk121]

Did anyone ever figure out how to add channel up down buttons to the 636 or road devil? Doesn't have to be for a magnum. Just curious for any radio.

 

[nomadradio]

There is no "any" radio hookup. Different radio brands connect the up/down buttons differently.

For a RCI radio, it's no big deal. Drill holes, mount switches. One pin of each switch goes to ground. The other pin on one switch goes to the up wire, the other switch to the down wire.

For other radios, the switches are treated differently.

73

 

[Mk121]

Ok that sounds easy enough. I saw someone using a 6pin rci mic with channel buttons on a Stryker and thought that was neat. I know they don't come with channel button mics from the factory.

 

[Tokin]

Ive seen rci up/down buttons installed on realistic 21-1173 desk mics so i would think the same could be done on a 636 hand mic.

 

[Handy Andy]

Those up down switches, for me, are not worth taking a good microphone and drilling holes to locate the up/down switches.

Why? Well, anyone with an Up-Down mic ever had to rewire one, knows, what Nomad is talking about...

Here's some examples...

Emperor TS-3010


Channel selector Is Grounded to select...
Left floating...

Realistic TRC-447

This one REQUIRES 8 volts, in, but REGULATES 5V for Channel Up
and Ground for Channel down - on Pin 4​

Just some extremes you'll find that when it comes to "doing up" a channel up and down feature on a handset...

A simple "Hey! Why Not?" - can turn into a nightmare of wiring and potential damages to the CPU taking in your selection...

That's ... After you've found enough room inside that handset to put in the switches and route power accordingly - because you can't just figure the radios own power is clean, strong or even provide enough power - for the selectors without having to modify the Mic socket to handle the extra wiring and pins needed - let along find those sockets and plugs to mate...

 

[Mk121]

I hear you there Andy. If I was to use a mic with channel buttons it would be one that came that way ,like how the rci and president mics come.

 

[Cabover Bob]

I recently acquired an HR2600 w/o the factory mic. Roger Bird has chipswitched it, and has advised me how to wire the buttons, which do not require any different voltages or additional components. I have some micro button switches from Mouser, hoping to get them installed in EC-2018, DM-452 or D104m6b, anyone have any luck with any of these ?

Todd