Repeater Cooling Fan On/Off Temps?

[dapaq2]

Anyone know what Kenwood has the On/Off temperature threshold set to in repeater models (such as NX700/NX800 and NXR710/NXR810 for example) that allow the cooling fan to be controlled by the temperature instead of continuous operation?

Thanks,
Doug

 

[toastycookies]

Anyone know what Kenwood has the On/Off temperature threshold set to in repeater models (such as NX700/NX800 and NXR710/NXR810 for example) that allow the cooling fan to be controlled by the temperature instead of continuous operation?

Thanks,
Doug

It is adjustable in the radio's programming.

 

[dapaq2]

Thank you for the reply and circuit diagram, but all I see in the software is changing the fans behavior by selecting "Continuous" or "Temperature". I don't see the ability to change temperature settings. Can you tell me where in the software I change the On/Off trigger temperature settings?

Thanks,
Doug

 

[phillmobile]

I looked in to this on a nxr800 computer says NO!
http://forums.radioreference.com/kenwood-forum/332255-nxr-800-fan-all-time.html

 

[dapaq2]

I appreciate your efforts in trying to help find a solution Phillmobile, But the NXR-700/800 repeater is not the same as the NXR-710/810 and they both use different KPG programing software.

 

[mmckenna]

For the NXR-x00 repeaters:

10) FAN
This is a cooling fan that discharges the heat in the
repeater generated due to transmission. This fan
starts rotating when the repeater is turned ON. The
fan will stop rotating when the temperature sensor
senses a temperature lower than the reference
temperature.

There is a high temp sensor on the finals board that will throttle back power when the board temperature reaches 83ºc or higher.

I looked up the specs on the temperature switch IC, and it's programmable from -40 to 100ºc.
Looking at KPG-109 for the NX-x00's, there is no field for changing the setting.

In the service software, there is a field where you can set it to room temperature as a way of calibrating it.

Nothing I could find in the service manual, function reference, customer support information, field programming reference, or the system programming reference, showed that it was adjustable.

Probably it's set by the firmware. In other words, Kenwood doesn't feel that it's something that should be messed with.

 

[dapaq2]

Mmckenna, do you see any way to adjust the on/off of the fan on the NXR-x10 repeaters? The NXR-710 is the model repeater that I am interested in making the on/off temperature adjustment to.

 

[mmckenna]

OK, I don't have access to the NXR-x10 programming software, so what I have may not match up with what it shows. But from the manuals:

Fan action has two options-

Continuous: Fan runs continuously unless the temperature is below 0ºc.
Temperature: Fan starts when temperature rises, stops when temperature drops.

Again, like the NXR-x00's, there is no setting I can find where you can adjust the temperature setting. Likely it's in firmware.

Can we ask why you want the fan to turn on/off a specific temperatures? Since the temperature switches are on the boards, they are looking at actual internal temperatures. Is it noise, dust or power consumption you are looking at?

 

[dapaq2]

The fan in an NXR-710 that I have, once activated to turn on by the thermostat, it will not shut off and the only way to get it to shut off is if I power off the repeater using the power switch and then power it back on, then the fan will shut off. Otherwise when the repeater is powered up "cold" the fan is off, and after several hours in standby, eventually the fan turns on, but the fan never gets told to turn off by the temperature sensors, the fan just runs continuously once it has been triggered to turn on. I would like to see if I can make some adjustments with the on/off threshold settings raising or lowing the temps to see if that resolves the issue.