On some of the Spectra radios with the x-5 or x-7 control heads, the radios ON/OFF button in the upper left corner of the head does not turn the radio off. It is always on as long as power is applied. The Ignition Sense settings in the RSS have no effect nor are other apparent options available in the RSS.
I seem to remember that enabling or disabling this button is a function of Jumpers inside the control head board.
If so which jumpers ( J1, J2 ? ) and which configuration enables the ON/OFF button ?
Enabling Spectra ON/OFF Button of -5 and -7 Heads
Moderator: Queue Moderator
Re: Enabling Spectra ON/OFF Button of -5 and -7 Heads
You are correct, there are a couple of jumpers that "bypass" the ON-OFF switch. These are those little 000 surface mount resistors.
Also: [quoting 60hzEE's post]
Sounds like someone installed JU7 on the back of the control head. This bypasses Q51, which is used to apply A+ when the power button is depressed and held.
Looking at the back of the head PC board, JU7's location is directly under the rather big FET in the lower right hand corner of the PC board. Right under the bottom soldered lead from the FET, oriented vertically. If you remove JU7 (or wire or solder bridge) across the pads, that should do it. There could he another jumper next to it, JU1. It should be removed for on/off switch T/R control. JU2, oriented horizontally, immediately to the left of JU7, should be installed. The chip jumpers should say "000" on top of them.
Also: [quoting 60hzEE's post]
Sounds like someone installed JU7 on the back of the control head. This bypasses Q51, which is used to apply A+ when the power button is depressed and held.
Looking at the back of the head PC board, JU7's location is directly under the rather big FET in the lower right hand corner of the PC board. Right under the bottom soldered lead from the FET, oriented vertically. If you remove JU7 (or wire or solder bridge) across the pads, that should do it. There could he another jumper next to it, JU1. It should be removed for on/off switch T/R control. JU2, oriented horizontally, immediately to the left of JU7, should be installed. The chip jumpers should say "000" on top of them.
Re: Enabling Spectra ON/OFF Button of -5 and -7 Heads
Thanks for the help.
I can see where having ignition control of the radio is practical in some applications, but it's vexing for mine. This is a big help.
I can see where having ignition control of the radio is practical in some applications, but it's vexing for mine. This is a big help.
Re: Enabling Spectra ON/OFF Button of -5 and -7 Heads
This is where we removed the jumper on a bunch of AVL radios. Real easy to do. Remove the jumper where noted in the pictures, just add one. This should solve your power problem.

View of head position for modification

Close up of wire to cut....

Close up of same jumper to cut...

Closeup of jumper after removal....

Final Photo of jumper removed.
Several years ago a bunch of AVL Spectra hit the market (I had a couple hundred of these) and were all constantly powered on. This was the mod to turn the heads back to normal.
GOOD LUCK! It's easy and simple to do.

View of head position for modification

Close up of wire to cut....

Close up of same jumper to cut...

Closeup of jumper after removal....

Final Photo of jumper removed.
Several years ago a bunch of AVL Spectra hit the market (I had a couple hundred of these) and were all constantly powered on. This was the mod to turn the heads back to normal.
GOOD LUCK! It's easy and simple to do.
Scott B.
"Never argue with seven men when you are carrying a six shooter..."
"Never argue with seven men when you are carrying a six shooter..."
Re: Enabling Spectra ON/OFF Button of -5 and -7 Heads
Excellent photos, very helpful, many thanks.
I just like having the radio available at all times and not dependent upon the ignition switch. There are times when you want to leave the radio on, but not the key in the ignition.
I just like having the radio available at all times and not dependent upon the ignition switch. There are times when you want to leave the radio on, but not the key in the ignition.