I have two Motorola GR500 repeaters, and for some reason, I got to thinking about which direction the cooling fan should be blowing. On both of mine, they are blowing INTO the repeater but asking ChatGPT, it said they should be exhausting the hot air OUT of the repeater. Which is right, or doesn't it really make a difference?
-
To anyone looking to acquire commercial radio programming software:
Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.
If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.
To obtain Motorola software see the Sticky in the Motorola forum.
The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.
For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).
This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.
Cooling fan direction on the GR500
- Thread starter Flameout00
- Start date
In most cases exhausting air out of an enclosure is more efficient. When my job was RF layout and packaging I tested air flow with clear plexiglass tops on enclosures and injected liquid smoke into the enclosure to watch the air flow and creation of eddies or dead spots. Air fans pointing inward were really bad except to cool an item directly in front of the fan where everything else heats up and suffers. Pulling air out of an enclosure provides much better cooling of everything in the enclosure and with radio heatsinks at the rear of a repeater enclosure a fan at the rear pointing outwards will pull lots of air past that heatsink in addition to removing heat in other areas.
That's some good information, thank you..
The GR500 enclosure itself doesn't seem very efficient though. It's certainly not air tight, but with the current situation of the fan blowing in, you can feel air being pushed out of all of the small openings, and hear the fan change pitch when going from open cover to everything closed up. I'm going to change it to exhausting the air out, and see how that works out
The GR500 enclosure itself doesn't seem very efficient though. It's certainly not air tight, but with the current situation of the fan blowing in, you can feel air being pushed out of all of the small openings, and hear the fan change pitch when going from open cover to everything closed up. I'm going to change it to exhausting the air out, and see how that works out
Looking at a picture of the GR500 tower I would not only pull air out of the enclosure, I would also cut some intake holes along the front sides around the radios to get a flow across the side of the radio then off the rear heat sinks out the back. If there are any vents in the back besides the fan opening I would block those as they will only provide an air bypass path that doesn’t help anything. You can’t vent a sealed enclosure, you need intake openings in a spot where it will drag air at good velocity across hot areas then out the fan.
I'm definitely going to do that. At first I though about venting from the side, but I think it would be better from the front, since the radio is mounted in that bracket. Venting the front should pull air across the radio better than the side would. Would it be beneficial to incorporate some type of air filter, or is that overkill?
That's a different enclosure than I was thinking, the tower version is what I was referring to. I would have to look that one over to get some ideas.
I guess that wasn't the best photo to use.
Maybe these will give a better idea of what it looks like
Maybe these will give a better idea of what it looks like
- Joined
- Aug 17, 2010
- Messages
- 1,360
we had one in a rather warm location where we added a 2nd fan to exhaust so the 2 were in a push/pull config. i never measured anything scientifically but over the next few years the customer no longer was replacing or repairing the PA every summer. push the cool air in across the PA, pull the warm air out to get rid of it. i don't remember exact details, but we basically cut a hole and mounted a 3 or 4 inch DC fan to blow out. noise was not an issue where this was located so we did not do any type of thermistor control and just let it run.
Muffin type fans typically live longer running all the time vs starting and stopping from a heat switch. Its probably better to use a heat switch to stick a resistor in line to cut fan speed to about half at cool temps then short out the resistor when it gets hot for full fan speed.
Thats the wall mount GR series. Installed many of them in factories and other industrial locations. We would install filters on them to keep some of the metal or cardboard out of the enclosures. Yes not super efficient for cooling but we always had them on low power to avoid the PA dying.The desktop ones were very similar for cooling. They even made a front cover for the desktop that limited even more cooling. Personally I dont think any of those were designed for continuous use even though many sales guys thought that was the perfect sale.
