GP300 Prog. Cable Question

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VA3XDJ
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GP300 Prog. Cable Question

Post by VA3XDJ »

Hi,

Would 7 volts DC at 700mA be sufficient (and safe) to use for a GP300 programming cable I'm building?

Thanks
Will
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Post by Will »

The radio requires 7.5 volts and that can also be used to supply the RIB thru pin 12 on the 25 pin connector.

You are only going to need the receiver energised for programming, so 150 to 400ma would be enough if you do not have the volume all the way up.

My programming adapter uses a wire in the programming cable going to pin 12 to supply power to the RIB.
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Monty
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Post by Monty »

Hello:

You can use a Fresh 9 Volt DC Battery for powering
the radio for programming.

One word of caution....If you are planning on building a
cable with Aligator Clips, ( DON"T ) as if you should slip
on holding the clip on the program surface, its possible
to turn the radio into a Brick real fast.

If you are planning to use a Old Battery Housing, Placement
of the Pogo pin is pretty critical since it has to " Slide Accross"
the Program Surface.

But, one thing for sure, if you go that route, you will have a
nice tight fit ,and we use Brand New housings for the ones
we make and offer to forum members.

Image
monty
Need help on a Program Cable or (/\/\) Rib Box ?
Contact me anytime/All availible / Free Support Info !

mail to: MSisco9939@aol.com
PLease avoid PM's whenever possible. Box gets too full.
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kcbooboo
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Post by kcbooboo »

I have a GTX portable that seems to use the same batteries and speaker/mikes as the GP300 series, among others. I borrowed a friend's home-made programming pack that has an internal battery. Worked fine for programming channels and modes and setting the squelch. BUT, there's insufficient power available for setting deviation, power, or frequency warp. I'd certainly opt for alligator clips to a bigger power supply for those occasions.

How do real Motorola service stations work on these radios when they need to transmit and program those parameters? I found it to be quite a pain to:

hook up the programming adapter
turn the radio on, wait for it to self-test (at least 6 seconds)
start RSS and make an adjustment
save the setting (goes through TWO reset/self-tests, 12 seconds)
turn off the radio
remove the programming adapter
slide on the battery
turn the radio on, wait for it to self-test (yes, another 6 seconds)
key the transmitter and take a measurement
turn off the radio
remove the battery
repeat from the beginning if it's not right

There's got to be a better way !

I'd like to see someone come out with a programming adapter that mounts to the radio where the battery does, but also provides a place where one could slide the battery onto the programming adapter - stack the adapter between the radio and the battery. That would allow the battery to power the radio for transmitting purposes. Yes, it would make the radio thicker, but it would eliminate all the swapping that I go through now.

When I had to do all of this to my GTX mobile radio, it went so much faster because the radio was adequately powered from the back and got programmed from the MIC jack in the front. Made alignment and adjustment take a few minutes instead of most of an hour.

Monty: is the adapter you have able to be opened for the purpose of bringing out the power leads so a user could attach it to a bigger supply, thus allowing transmissions during programming? I'll send you mail for further inquiries.

Bob M.
VA3XDJ
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Post by VA3XDJ »

I will be using a dead battery casing and pogo pin to build the cable along with the DB25.

The RIB is powered thru a wall wart to avoid messing up a codeplug when not sure how much juice is left in the battery.

So 7 volts would NOT be safe or sufficient for reading/writing to radio ONLY?
nyghthawk
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Post by nyghthawk »

How do real Motorola service stations work on these radios when they need to transmit and program those parameters?

the oem motorola programmer has a passthrough so you put the programmer on the radio where the batt goes and the batt goes on the back of the programmer. also it has a banana plug pigtail so you can run 7.5 vdc from a power supply.
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kcbooboo
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Post by kcbooboo »

The pass-through design seems quite logical. I've never seen one. All the programmers on eBay were built from battery cases and entirely replace the battery. If I could get such an empty case, I'd just bring out my own pigtail leads and be done with it.

Is there any voltage regulator built into the units that use a 9V battery for power, or can the radio deal with "nominal" 7.5V and handle 9V or even 14V from a car?

Bob M.
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sb
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Post by sb »

Hi!

Here are some pictures of Motorola HKN9755A Cloner/Programming assy.

Image
Image
Image
Image
Image
Image
Beno, s56kz
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kcbooboo
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Post by kcbooboo »

Thanks for the excellent pictures.

After looking at the "fine print", now I know why Motorola wants almost $200 for this unit. It's not just a battery eliminator with a programming cable attached - this one has the ability to clone radios as well, so there's at least a computer with some RAM inside to do all of this. Hopefully there's a memory backup battery in it as well.

I'd almost be better off buying the manual for one of these and trying to buy just the case components so I can put it between the battery and radio and add my own cables. I don't need all the smarts inside - just the ability to run the transmitter from RSS for alignment purposes.

Bob M.
Nand
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Post by Nand »

There exist two different programming cables for the GP300. The above picutered version with the built in cloning capability (HKN9755A) and the simple one without any smarts in it (HKN9857A). Both look the same other than the little control panel on the side for the cloning version. The real surprise is that both cost about the same, about $220.00 USD.

As for power, both units have a crowbar voltage protection circuit inside that is directly connected across the + and – power terminals. This crowbar trips at about 10 volts and should blow the fuse in the power leads that is supposed to be present. A reverse power protection diode is also present. Operating voltage when fed from an external power supply is about 7.5 volts. There is no voltage regulator inside this box. All power wiring is connected in parallel meaning that when an external power supply is used, a battery should not be used since it would be connected directly across the power supply. Likewise, when a battery is used, power will appear across the banana plugs on the power cable.

As for the original question, is 7 volts at 700mA enough? I would say yes, assuming that the voltage is slightly higher at the smaller load that the radio draws during RX and programming, and also because the radio will operate fine at 7 volts. But when doing an alignment with the RSS that causes the transmitter to be keyed, the voltage will likely drop below the minimum voltage causing the radio to reset. This actually happens from time to time in our setup because we replaced the guts in the programming cable with an 8-volt regulator that only can handle 1 amp. This allows us to just run from a common 13-volt power supply. For TX tuning, we use a different unmodified cable. It never caused a corrupted code plug running at low voltage or having the radio reset.

Nand.
Last edited by Nand on Mon Oct 04, 2004 3:34 pm, edited 1 time in total.
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kcbooboo
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Post by kcbooboo »

For laughs, and since I had Motorola on the phone already, I inquired about the 9857 unit: only $195. Good thing I was sitting down. The thing can't cost that much in parts alone unless there's gold inside it.

Bob M.
Nand
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Post by Nand »

You will find that the cloning capable box is about the same price. It can also be used with the RSS.

Nand.
VA3XDJ
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Post by VA3XDJ »

Thanks for the straightforward answer Nand.

It will be used for reading and writing to the radio but not for TX or alignment.
Nand
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Post by Nand »

Just make sure the voltage does not go over 9 volts at any time to be on the save side.

Nand.
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