Module Temp in 7UAFS, 8UAFS
04-14-2004 | 04:13 PM
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From: Langley,
BC, CANADA
Module Temp in 7UAFS, 8UAFS
I recently purchased an 8UAFS from a fellow in our club. I've used it a number of times with no problems. The last time I used it, I happened to touch the Tx. module on the back and noticed it to be warm. I still have my older 7UAFS and didn't recall the module being warm in it.
I did some tests with a temp probe on both transmitters with the following results. The 7UAFS after 15 minutes 73 degrees, after 30 minutes 87 degrees. The 8UAFS after 15 min. 95 deg. after 30 min. 102 deg. (Ambient temp. was 68 deg., Antennas fully extended). I've read other posts on this subject and temps around 102 seem to be OK. I've used the same module in both Tx. and even swapped the antennas thinking it could be causing a fault. The result is the same, the module when in the 8UAFS runs warmer.
If all transmitter circuitry is in the module why would there be a difference in its temp when in the two Tx. The 8UAFS range checks fine, and works great. I've been using Futaba radios since my first 4NBL and they've never caused me a problem. Is this something I need to be concerned about? Thanks for your help. Jim
I did some tests with a temp probe on both transmitters with the following results. The 7UAFS after 15 minutes 73 degrees, after 30 minutes 87 degrees. The 8UAFS after 15 min. 95 deg. after 30 min. 102 deg. (Ambient temp. was 68 deg., Antennas fully extended). I've read other posts on this subject and temps around 102 seem to be OK. I've used the same module in both Tx. and even swapped the antennas thinking it could be causing a fault. The result is the same, the module when in the 8UAFS runs warmer.
If all transmitter circuitry is in the module why would there be a difference in its temp when in the two Tx. The 8UAFS range checks fine, and works great. I've been using Futaba radios since my first 4NBL and they've never caused me a problem. Is this something I need to be concerned about? Thanks for your help. Jim
04-15-2004 | 07:41 AM
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From: Va Beach, VA
RE: Module Temp in 7UAFS, 8UAFS
Futaba recommends pulling out a few lengths of antenna if your TX will be on for any length of time. Check the temps with the antenna pulled up.
04-15-2004 | 04:22 PM
#3
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RE: Module Temp in 7UAFS, 8UAFS
With the transmitter antennas fully-collapsed, the output stage of the module gets overloaded. The output transistor will heat up. If it gets too hot, it will fail. Lower range will show you if something's wrong. If range is unaffected, the transistor's working OK, but total service life may be compromised (it's not certain).
Just pull the antennal all the way out and then put it all back in except for the largest section. Leave that one out when you're programming or operating your transmitter for an extended period of time. You'd do this when you're setting up your system in the model on your workbench.
Just pull the antennal all the way out and then put it all back in except for the largest section. Leave that one out when you're programming or operating your transmitter for an extended period of time. You'd do this when you're setting up your system in the model on your workbench.
04-15-2004 | 05:44 PM
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From: MARANA, AZ,
RE: Module Temp in 7UAFS, 8UAFS
ORIGINAL: NoARFS4Me
I recently purchased an 8UAFS from a fellow in our club. I've used it a number of times with no problems. The last time I used it, I happened to touch the Tx. module on the back and noticed it to be warm. I still have my older 7UAFS and didn't recall the module being warm in it.
I did some tests with a temp probe on both transmitters with the following results. The 7UAFS after 15 minutes 73 degrees, after 30 minutes 87 degrees. The 8UAFS after 15 min. 95 deg. after 30 min. 102 deg. (Ambient temp. was 68 deg.,Antennas fully extended). I've read other posts on this subject and temps around 102 seem to be OK. I've used the same module in both Tx. and even swapped the antennas thinking it could be causing a fault. The result is the same, the module when in the 8UAFS runs warmer.
If all transmitter circuitry is in the module why would there be a difference in its temp when in the two Tx. The 8UAFS range checks fine, and works great. I've been using Futaba radios since my first 4NBL and they've never caused me a problem. Is this something I need to be concerned about? Thanks for your help. Jim
I recently purchased an 8UAFS from a fellow in our club. I've used it a number of times with no problems. The last time I used it, I happened to touch the Tx. module on the back and noticed it to be warm. I still have my older 7UAFS and didn't recall the module being warm in it.
I did some tests with a temp probe on both transmitters with the following results. The 7UAFS after 15 minutes 73 degrees, after 30 minutes 87 degrees. The 8UAFS after 15 min. 95 deg. after 30 min. 102 deg. (Ambient temp. was 68 deg.,Antennas fully extended). I've read other posts on this subject and temps around 102 seem to be OK. I've used the same module in both Tx. and even swapped the antennas thinking it could be causing a fault. The result is the same, the module when in the 8UAFS runs warmer.
If all transmitter circuitry is in the module why would there be a difference in its temp when in the two Tx. The 8UAFS range checks fine, and works great. I've been using Futaba radios since my first 4NBL and they've never caused me a problem. Is this something I need to be concerned about? Thanks for your help. Jim
04-16-2004 | 11:53 AM
#5
My Feedback: (11)
RE: Module Temp in 7UAFS, 8UAFS
If the module cover never becomes more than comfortably warm, you don't have a problem. The output transistor will emit some heat. The module cover should never develop a hot spot that's uncomforably warm/hot. That would indicate a problem.
