Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Winter project using a Harbor Frieght Temp gadget to monitor my amp - where?  (Read 1064 times)
KC1GCG
Member

Posts: 136




Ignore
« on: December 06, 2017, 08:14:29 AM »

Hey all,
Got this idea for a fun and hopefully useful project. I have had one of those infrared Thermometers from Harbor Freight that I bought many years ago and I noticed they are on sale now for only $17! These are the ones where you point and shoot using an LED to pick your target and they give you a pretty accurate temp.

I want to disassemble one and make a box to put on top of my amp to display the temp of some comp in the amp. If you could constantly monitor the temp of one item what would it be? If the tube, where? Or maybe the plate choke?
Ideas appreciated. My goal is to mount the temp probe's guts someplace inside that will not overheat them (or I can put it external with some wires) and have the sensor point at the comp to be monitored and "remote" the temp display with some wires so that it is on top of the amp facing me above the meters.
I also plan to wire it on all the time but not sure of the life of it as its made for intermittent use with a squeeze trigger. But at these prices if it fails due to that I figure I can get another and wire up a push button so that I could periodically check it.
Anyway just thunking for a winter project that may be fun for me.... like I don't have enough  looking at the Hallicrafters and Heathkit stuff I have collected this year:)

Back story you can skip if you like...in the late 70's and early 80's I worked as Test Dept Mgr for what I think was the first non contact temp measurement company that used fiber optics to monitor temps. They were used in many applications such as heat treating, injection molding, semiconductor testing, band saws and I even tested a couple that Rockwell used to develop the heat shields for the space shuttle. Very cool job now that I look way back on it.
So probably 10 years ago when I saw this little hand help temp device I fell in love with it and could not believe how far the tech had come and the prices had fallen.
I have used it for many things....first was in my boat with the big inboard engine that was over heating and it helped me figure out by watching the temps rise in various parts of the engine that the risers were shot. I've used it at home and in rentals to periodically check the temp of breakers in the main panel and have found several running hot that were due to some corrosion starting. Maybe saved me a house fire or two! I keep one next to my wood stove in case I think I overloaded it and can monitor the pipes and walls until I get it calmed down. They are also great for the other end of the spectrum for finding frozen pipes. If the pipes have not broken but froze  you can use it by scanning along pipes and seeing slightly above freezing temps of say 34f and then when you hit the location of the freeze tada they drop right down to 32f. That accurate. Then a good ole hair dryer and finding the source of the cold air helped me fix these problems quickly in new rentals I bought. I recommend them even if you don't use it on an amp or other electronics.

Thanks in advance
John K1JRF

Logged
K8AXW
Member

Posts: 6378




Ignore
« Reply #1 on: December 06, 2017, 10:28:58 AM »

I have found it interesting to monitor the exhaust air from my amps with a "no-contact IR monitor" to see where the temps go.  I've checked from "idle" to "hard run." But I don't monitor this constantly.

I've considered the same as you.....converting one of the "no-contact" IR devices to provide constant monitoring of amp components but figured I'd run into RF problems so dropped it since I've always had more important things to do.

They are GREAT for checking where cold air is coming into the house in the winter. They can pay for themselves with one use!
Logged
KC1GCG
Member

Posts: 136




Ignore
« Reply #2 on: December 06, 2017, 03:40:59 PM »

K8AXW,'Thanks for the reply.
I too was wondering about RF bothering it and have moved the handheld gadget around the ext of the amp while running and have not seen it act strange ie RF getting to it. I was thinking worse case some shielded cable to mount most of it outside the amps chassis or if a part of the tube is a good idea to monitor then I can probably set that up thru the exhaust holes and keep the whole thing external.
Also wanted to mention to anyone interested that I have an SB1000 if that affects what I should monitor (ie it is prone to something overheating that I have not read about)
Thanks
John K1JRF
Logged
AC2RY
Member

Posts: 310




Ignore
« Reply #3 on: December 06, 2017, 05:45:11 PM »

K8AXW,'Thanks for the reply.
I too was wondering about RF bothering it and have moved the handheld gadget around the ext of the amp while running and have not seen it act strange ie RF getting to it. I was thinking worse case some shielded cable to mount most of it outside the amps chassis or if a part of the tube is a good idea to monitor then I can probably set that up thru the exhaust holes and keep the whole thing external.
Also wanted to mention to anyone interested that I have an SB1000 if that affects what I should monitor (ie it is prone to something overheating that I have not read about)
Thanks
John K1JRF

I do not see what should be monitored via IR other than tube plate temperature. For anything else regular contact temperature sensor is sufficient.
Logged
K8AXW
Member

Posts: 6378




Ignore
« Reply #4 on: December 06, 2017, 08:14:04 PM »

RY:

Quote
I do not see what should be monitored via IR other than tube plate temperature. For anything else regular contact temperature sensor is sufficient.

I kinda agree but measuring the "plate temperature" .....how?  I think measuring the exhaust air temp. would give sufficient information.

I think the point John was trying to make was that the "no-contact" IR sensor indicators is a very convenient tool to have around the house.

The first affordable one I saw and bought was a Radio Shack IR thermometer and have used it countless times.  The convenience and speed of the no-contact thermometer is great.

The very first one I saw was used by a contracting company to check and photographically record the temperatures of the hundreds of wiring connections in our old power house.  It consisted of a pack that was carried on the chest and the size of a backpack! 

I have no idea what this company charged us but I'm sure it paid for itself because they found several hot joints that could have catastrophically failed at some future time. 

My cheap instrument has paid for itself many times over by detecting where the cold was getting into my house. (I was also able to get the XYL off my donkey when I learned where the cold draft was coming from that was bothering her when she set on the couch)

I have used it countless times to monitor the temperature rise in large power supply transistors. Same with transformers in homebrew gear. 

The use of this thing is almost limited by one's imagination.....and if nothing else, it's one of those tools that lay around for years doing nothing but when you need it, you got it!

John, JRF, made a great suggestion.
Logged
N3QE
Member

Posts: 4938




Ignore
« Reply #5 on: December 07, 2017, 05:29:16 AM »

I do not see what should be monitored via IR other than tube plate temperature. For anything else regular contact temperature sensor is sufficient.

With a small enough spot this could be used to check tank coil heating. This could be especially relevant for someone trying to determine the limit of a ferrite tank.

Or look for padding capacitors that are "running hot" prior to complete failure.

Most folks who do this kind of small-scale analysis are using IR cameras to look for the hot spots in the assembly compared to "normal". And they might test hundreds of units a day looking for manufacturing faults or maintenance needs, so they know what "normal" is just by looking at the IR picture. If you only have a sample size of one you probably don't know what normal even is.
Logged
K8AXW
Member

Posts: 6378




Ignore
« Reply #6 on: December 07, 2017, 09:08:56 AM »

I have seen just one IR camera...which was the one the contracting company used.  The "camera" part was included in the "chestpack" and the actual probe was like a big gun connected to the chestpack by a cable.

Contact temperature thermometers (looked like a 3" steel 'skid' on the end of a 3ft pole with the held end containing the digital readout temperature equipment.  The "skid" was applied to our paper machine dryer rolls for a minute to get a readout of the roll temperature. (when you're checking 30 or more rolls on a paper machine, a minute is a LONG time!)

They eventually switched to a no-contact IR meter and the time required to get a roll temperature reading was reduced to about 3 seconds per roll.

To somewhat repeat myself, the no-contact IR meter is one tool most hams never think about having.
Logged
WE6C
Member

Posts: 27




Ignore
« Reply #7 on: December 07, 2017, 10:09:13 AM »

As an auto mechanic I've used one for years and it gets a lot of use. I also found by adding insulation in a wall in my house the wall temperature increased by 15 degreesF in the winter! The tool has unlimited possibilities.

Monitoring the temp inside an amp sounds like a good idea but is a challenge as you're discovering. Maybe just monitoring the general inside temperature will be a good enuff guide.

Bob
Logged
VK6HP
Member

Posts: 186




Ignore
« Reply #8 on: December 08, 2017, 08:02:37 AM »

If I had the capability to do so, I'd be doing all I could to use the non-contact sensor to measure the actual plate, or tube envelope, temperature. Almost everything else commonly measured is a proxy for that.  It's a particular waste to measure the outlet air temp with the IR sensor since the blower/fan is high on the list of potential failure items.  To realize the advantage of the IR sensor over traditional contact sources, you really want to use it to quickly get on top of potentially damaging faults before they become critical.

73, Peter.
Logged
N3QE
Member

Posts: 4938




Ignore
« Reply #9 on: December 08, 2017, 08:06:12 AM »

I gotta put one of these on the top of my amp!


Logged
N3QE
Member

Posts: 4938




Ignore
« Reply #10 on: December 08, 2017, 08:10:56 AM »

If I had the capability to do so, I'd be doing all I could to use the non-contact sensor to measure the actual plate, or tube envelope, temperature. Almost everything else commonly measured is a proxy for that.  It's a particular waste to measure the outlet air temp with the IR sensor since the blower/fan is high on the list of potential failure items.  To realize the advantage of the IR sensor over traditional contact sources, you really want to use it to quickly get on top of potentially damaging faults before they become critical.

After a local lost an almost-new 3CX1500A7 when the blower died, I put a vane switch in my amp so that in case of loss of airflow the amp will shut down. Due to the cabinet design of my amp, the way cold air is sucked first over the power supply compartment before being sucked in the blower and sent through the tube, I could put the vane switch outside the RF compartment.
Logged
WB8VLC
Member

Posts: 427




Ignore
« Reply #11 on: December 09, 2017, 01:08:48 PM »

I'm just starting a project using the following melexis ir sensor with some 5 dollar Arduino's to monitor the input and output Pin diode temperature in my 600 watt and 1200 watt solid state PQL sourced HOMEBREW amps as the qsk t/r switch's pin diodes are the only part of my amps that are un-monitored.

I'm still working on the code and still playing around in the decision phase of tying the arduino output in to my amps existing shutoff protection system.


https://www.newegg.com/Product/Product.aspx?Item=2S7-00VK-00P54

hookup guide for the above sensor, newegg has the same sensor at 1/2 sparkfuns price; however, sparkfun, arduino and  and adafruit have more code info for this sensor.

https://learn.sparkfun.com/tutorials/mlx90614-ir-thermometer-hookup-guide?_ga=2.206868374.424536640.1512417020-1541512035.1509995152

https://create.arduino.cc/projecthub/TheGadgetBoy/diy-a-5-minutes-contactless-oled-thermometer-with-arduino-857a1d

https://learn.adafruit.com/using-melexis-mlx90614-non-contact-sensors/wiring-and-test
« Last Edit: December 09, 2017, 01:12:40 PM by WB8VLC » Logged
N4MQ
Member

Posts: 146




Ignore
« Reply #12 on: December 10, 2017, 04:41:59 AM »

I purchase a lot from harbor freight and always use the 20% off coupons, but in this case the sources at ebay have the IR guns for half price and free shipping.  Ebay has supplied me most of the parts for my projects at cant beat prices, 3ag fuse assortment for 72 fuses at less than 4 $ shipped!

Here is link:

https://www.ebay.com/itm/Temp-Meter-Temperature-Gun-Non-contact-Digital-Infrared-Laser-IR-Thermometer/172533295215?epid=2086199725&hash=item282bc9286f:g:ykMAAOSwNWxaAebY

Enjoy Woody

BTW I use a thermometer on my rig with probe on outlet screen of my Ameritron amp: $3.70 SHIPPED!!

https://www.ebay.com/itm/Digital-LCD-Indoor-Outdoor-Humidity-Hygrometer-Thermometer-Meter-Probe-Cable-C-F/221816312512?hash=item33a54852c0:g:XZEAAOSw3ydVlkGl
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!