Batboard

I have 2 hi power Spectras in my suburban (T83,T84) and every time you turn the power off at the control head or if you happen to leave the radio on and start the truck the radios power cycle and it comes out of scan mode, and if you happen to be in a mode other than the home mode the radio reverts to the home mode. I have pulled the drawers out and swapped them with the drawers in my car which do not have this issue and the same thing happens using different control heads and cables...if anyone has any ideas of what the issue is please let me know so i can "fix" things so i dont have to turn the scan back on every time i get in and start the car or turn the radios back on. Thanks.

I'm almost willing to bet that when you start the truck, the voltage to the radio is dropping to below 11 VDC.

but if i just turn the radio off for a bit and turn it back on then it still jumps out of scan mode, my other spectras dont do this, however the voltage does drop to 9.85-9.90 volts when started...

ffemt1764 wrote:but if i just turn the radio off for a bit and turn it back on then it still jumps out of scan mode, my other spectras dont do this, however the voltage does drop to 9.85-9.90 volts when started...

...which most likely shuts the radio down for an instance. As for your other Spectras not doing the same thing, are the programs identical?

yes the radios all power cycle, good and bad ones...the ones in the car are d43,d44 remote kits and when they power cycle they remain in scan mode when they come back up. the truck radios when cycled jump out of scan

Loss of scan state and mode state generally signify a loss of power (<~11.0VDC) on the main power connector. As to why that is happening, I'd have to prowl around the rig with a DVM.

" Loss of scan state and mode state generally signify a loss of power (<~11.0VDC) on the main power connector. "

RKG is right on target....

The main source of battery for the radio MUST direct to the battery. The source for the Green wire at the control head MUST be from the same source, not thru some fuse box, switch ect;.

Also check the ground a at the radio main power lead. Some trucks ect, can have poor grounds in the body and frame causing just enough loss to have the continious 5 volt regulator in the Spectra shut down and the scan and other settings get erased from memory.

Some Spectras are more prone to the loss of settings than others on low or loss of voltage, and I do not have the answer for this.. the circuit IS the same.

I supose the memmory keep voltage could be beefed up so it takes a longer low voltage on the radio before the regulator drops out.

Ok, so I understand all this correctly, the big red wire from the drawer unit and the green control head wire must BOTH go directly to the battery? The big red power wire is already going directly to battery, and I have the radios grounded to a know good factory ground that maintains >5 vdc when the vehicle is started...just want to be sure that I understand all this before I go running wires to places and such.

Let me ask a few simple questions.

How old are the batteries in the Suburban?

Is your engine by any chance a diesel?

The bottom line like others have said is you battery voltage is going too low while cranking the engine. My bet is the batteries are in the 3 year or older status. If so, by any chance is the clock time also going wacky. Like it resets to 12:00 when you start the engine?

One of my old bosses told me he had to reset the clock time on the radio almost every day. My first question was how old the battery was. he said 3.5 years. Told him to get a new battery. About 4 days later, he hads to jump start the car. Asked him when was he planning to put a new battery in. After having to go save the wife from the shopping mall, he bought a new battery.

No more clock time going bananas and the car starts every time now.

Jim

Battery less tthan 1 yr old, gas 350 eng, and the clock does not lose its memory...the spectras do remember if the sirens were on or off when the power cycles but they dont remember modes or scan settings. Everything else remembers what it should when the truck starts.

There really isn't any utility in speculating. Put a DVM, preferably a recording one, on the power line and see what happens to voltage at the radio.

It is also theoretically possible that some degradation within the radio causes it to dump the volatile memory at something well above ~11.0VDC, but you'd have to ask someone who knows more about Spectras at the board level than I do.

Voltage on the main power lead at the radio drops from 12.55 to 11.35 when the truck is started, but the voltage on the orange and green wires drops to the 9v range when started, but they do get their power from the fuse block...so i am going to run them directly to the battery also and see what happens there unless you guys have another idea on this whole wacky situation.

Mike, are these A9's?

Yes, Will, these are A9 radios

I checked the voltage at the battery today, when the truck is started the voltage at the battery drops to 11.3-11.1 vdc everytime you start it, however at the main power distibution block the power drops to 9.5 vdc when the truck starts, so I am assuming that the solution to the problem with the viable memory is the battery direct hookup...going to try and finish that this afternoon and get back to you guys.

Hi, I am new to this forum and this is my first post so if I make a mistake please let me know. I do all the installs and repairs for the air base here and have a few problems with fire vehicles and loss of power. Naturally I am always to blame but soon find out the battery, or something drainging the battery other than my radios, is the cause.

As far as this post is concerned I have some questions also. I agree that the green wire needs to have a constant power supply. When you start the vehicle do the radios power up or do you have to press the power button. If they start on their own then I would believe the wiring is ok. I have one suggestion. Since the mode reverts back to the home mode do you have that mode programmed for scan. Remember you cannot turn on scan if the radio channel/mode is not programmed to scan. It must be on a channel/mode that has the option to scan.

As DJP126 said I would make sure the programming is identical. If it isnt then it is hard to isolate a problem.

I see everyone here talking about power problems, but I am wondering what the power-up option is set for in RSS radio-wide options- is it set for last state?

Dear ALL
I have the same problem and I think it is the emergence switch is not shorted. I have the radio in the house and when the radio is turned on, you must press the emergence button and then the radio will scan. Did you make the cable 2 to 8 must be grounded?

I will be able to try this weekend when I get home

Andrew

The radios have A9 heads with the slider power switch. Applying constant power to the green wire has no effect, if you start the truck or turn the radio off then back on no more scan and back to home mode they go. The home mode in both radios is set as the #1 priority in the scan list, no surprise there use fire people love to have the home mode as pri 1...Rick I am not seeing this power up option in my RSS, if you could please point me to it that would be great...and as for the emergency idea the emergency button in each radio is programmed for EMERGENCY operation and identifies as such on our dispatch console, so I really dont want to go pushing it unless i really want the whole world rushing to me...I mainly enabled this feature because I am also a medic and sometimes dispatch doesnt always get the "right" information when it comes to scene security/safety and all. This problem is more an annoyance than anything...just wanted things to be the same from vehicle to vehicle...