RCI 2980 - DC connection for ext pwr

[jrd426]

Hi guys, i have a 2980 that i would like to run off of a 13.8vdc external power supply when needed. Any suggestions on connection to main board and if i am able to use the radios power button. I assume i would need to install a ac/dc switch like seen on all base radios meant to be able to run either way. Safety is of course a concern as well. Thx

 

[brandon7861]

Thats different. The schematic (looking at the 2980WX) shows the power switch after the regulator, so the regulator is always powered when the radio is plugged in. The output of the 13.8v regulator goes to the power switch and to the WX board, so the wx board is also powered regradless of the state of the power switch. If your radio is the WX version, there may be some trace cutting (or extra wire moving) to make it work right. If not the WX version, it should be as simple as replacing the power switch with a single pole dual throw toggle switch with the other side going to the DC source.

 

[nomadradio]

I assume i would need to install a ac/dc switch

That's the simple way. Can't just connect external DC to the radio where the internal regulator is connected. Feeding external DC power this way with the AC plug pulled out would put the equivalent of reverse polarity onto the radio's internal regulator circuit. Reverse DC polarity is never kind to transistor circuits.

You could insert a diode between the output of the radio's voltage regulator to prevent this, but the switch wins hands down in the simplicity department.

73

 

[jrd426]

I appreciate the comments on this guys. I think i will go with the rear mounted ac/dc switch and adding a panel mount 12vdc connector as well. The radio still has its original power supply which i was considering replacing with something like a meanwell switching supply. Im wondering if the black box power supply failures i read about is more common with the more powerful bases like the 2990 and up and maybe not so much on the saturns / 2980s with less pull on the internal supply. Swapping the original pwr supply might be a next winter project. Best and 73s

 

[nomadradio]

more common with the more powerful bases like the 2990

Much more common. We refer to the original Turbo/Stonewall/2990/Eagle 5000 power supply as "SUICIDAL".

As such, we replace it with a switchmode unless the customer says otherwise.

The leftover power transformers get sold on Ebay. Pretty sure the one listed now is number 26.

73

 

[Recon]

Hi guys, i have a 2980 that i would like to run off of a 13.8vdc external power supply when needed. Any suggestions on connection to main board and if i am able to use the radios power button. I assume i would need to install a ac/dc switch like seen on all base radios meant to be able to run either way. Safety is of course a concern as well. Thx

When needed? For loss of home power source?

 

[Recon]

Hi guys, i have a 2980 that i would like to run off of a 13.8vdc external power supply when needed. Any suggestions on connection to main board and if i am able to use the radios power button. I assume i would need to install a ac/dc switch like seen on all base radios meant to be able to run either way. Safety is of course a concern as well. Thx

Is your intent to have communication if and when there is a loss of 110/220 AC power?
A well maintained deep-cycle marine battery and an inexpensive / basic 40 channel CB radio would be one option.
I would not keep the battery in the living area of the house. In a ventilated cellar, sunporch or garage would be OK.

 

[jrd426]

True enough Recon just using a mobile radio / battery. I figured it would be a good option to be able to give the stock power supply in the base a break of sorts being able to use an external power supply. Not really a requirment but a would be nice if worth the effort 73s

 

[jrd426]

Much more common. We refer to the original Turbo/Stonewall/2990/Eagle 5000 power supply as "SUICIDAL".

As such, we replace it with a switchmode unless the customer says otherwise.

The leftover power transformers get sold on Ebay. Pretty sure the one listed now is number 26.

73

Hi nomadradio, if i were to replace the internal power supply guts on my rci2980 base with a switching type supply would I need to insulate it from the chassis or fasten it to the interior chassis / steel. Thank you

 

[nomadradio]

Switchmode power supplies come in more than one form factor. I recommend the "enclosed" variety that have a metal skin surrounding them. This type is meant to be bolted to a grounded metal chassis. The so-called "open" types that don't enclose the guts inside a metal shield will radiate RF noise into your receiver and raise the noise level, even when no antenna is attached. Makes it hard to hear a weak station. Oddly enough, the naked types are cheaper than the ones that come with clothes. The shielded type is just better for use in a radio.

You may find it beneficial to add a ceramic disc capacitor, like a .05uf or .01uf from one or both of the DC output screws on a switchmode supply, the other side of the cap to ground. Most of them are already filtered for RF noise, but not all.

73

 

[jrd426]

Switchmode power supplies come in more than one form factor. I recommend the "enclosed" variety that have a metal skin surrounding them. This type is meant to be bolted to a grounded metal chassis. The so-called "open" types that don't enclose the guts inside a metal shield will radiate RF noise into your receiver and raise the noise level, even when no antenna is attached. Makes it hard to hear a weak station. Oddly enough, the naked types are cheaper than the ones that come with clothes. The shielded type is just better for use in a radio.

You may find it beneficial to add a ceramic disc capacitor, like a .05uf or .01uf from one or both of the DC output screws on a switchmode supply, the other side of the cap to ground. Most of them are already filtered for RF noise, but not all.

73

Awesome. The supply i have is a 30a meanwell i believe. Its fully enclosed. I will mount it direct to the radio chassis then when i do the swap. The 30a is overkill i guess but its what i have here. I was wondering about the ps metal case sitting direct on the radios metal chassis but have my answer The 2980 has its original 2 prong ac power cord and i was thinking if I should replace that 2 wire ac cord to a 3 wire 2 plus ground when i do the swap to this switching pwr supply? Thx

 

[jrd426]

And thanks also for the tip on adding the disc caps.

 

[nomadradio]

Just be sure to include a 5 Amp fuse, or 6 Amp if it's a MOSFET-final radio in the DC wire that leads to the main circuit board. Nothing wrong with an overkill power supply that will never break a sweat. Just don't want to "overkill" the radio if something were to break down later on.

Didn't take long to learn that this is necessary in every high-power "black" base radio. Won't send one home without it.

73

 

[jrd426]

Yes. I have already added that inline fuse after other reading on these type base radios. What are your thoughts on replacing the stock 2 wire ac cord with a 3 plonger to connect to the new fangled pwr supply ? Im guessing yes but would appreciate your input on needed / good idea. 73s

 

[nomadradio]

Three prong cord is just a good idea. If you always bolt a ground wire to the radio without fail, maybe it's redundant. But the third prong on the power plug, and the third wire bolted to the radio chassis is just a safety measure. You'll be pissed if you leave it off and get zinged down the road.

73