Astro Spectra power switch, have to turn on radio everytime

[VSP5151]

We have a large number of Astro Spectra mobile radios. Some of them power up when we start the vehicle and the charge guard turns on. Other radios required the power switch to be pushed to turn them on. All are wired identically. I saw nothing in RSS to cause this power up change. I saw no jumpers in the control heads. Any help?

[Ranger522]

What type vehicles are the radios installed in?

The ASTRO Spectra control head requires a certain minimum voltage* (8.6 Volts) to remain powered up. In some vehicles (Ford Crown Vic and others) the voltage drops during start-up allowing all power to be devoted to the starter. The AS will power down during the start and, dependent on the control head**, power-up after voltage is restored.

*The vehicle's battery/charging system condition may contribute to this problem if all of the AS's are installed in the same type vehicles.

**The W4 control head will auto power-up due to the on-off position off the knob, your problem is probably due to the push-button design, requiring the user to power the radio on after the reset.

See this announcement:

This Bulletin Number is PSB F-454

APC - 221,581, 604, 617, 624
Date: October, 1994

Memo To: PSB Mailing List

From: Radio Systems Product Operations/Product Services, Plantation

Subject: Spectra Radio Reset During Vehicle Engine Starting

Symptoms: The Spectra mobile radio will sometimes reset and revert to the default settings while the vehicle engine is being started.

Potential Problem Radios: All Spectra mobile radios.

Cause: As mentioned in the Spectra Detailed Service Manual (68P80102W61), a reset circuit on the command board monitors the 9.6 supply, and will reset the radio if this supply is not present because of too high or too low battery voltage. The radio remains in reset until the supply returns to a voltage which allows the 9.6 Volt supply to recover. This range is from 8.6 V to 18.0 Volts. During engine starting, the vehicle voltage may drop below the 8.6 Volt level resulting in a radio reset when the voltage recovers.

Corrective Action: If in fact the battery voltage drops below the 8.6 Volts, a reset is normal. If the battery voltage is above 8.6 V and a reset occurs, check installation and wiring. A larger capacity battery or a battery back up device may be used to insure that the battery voltage doesn’t drop below the lower limit of 8.6 Volts.

This bulletin is for Information Only. No warranty is implied.

[jmr061]

Are these in a police/public safety use vehicle. If they are in my opinion the radio should be hot and should be turned on and off with the radio power switch or a master switch.

I believe the w5/7 control heads will power up with ignition if the ignition wire to the radio gets power and the radio is turned on in the first place. Example, car is running and radio is turned on. Ignition wire of radio hooked to ignition of car and main power wire hot all the time. You shut the car off, radio goes off, turn the car on and the radio goes on. Now if you have the car on and use the power button the the control head to turn it off then the radio will not power back on when the car is turned back on.

I think this is they way the work, I always wire them hot though.

Jason