Topics

Easy, Inexpensive Cooling Fan, Excelway Case

Arvo W0VRA
 

Jack, W8TEE
 

Is the fan quiet, or does the rcvr pick it up?

Jack, W8TEE

On Wednesday, June 27, 2018, 9:53:51 AM EDT, Arvo KD9HLC via Groups.Io <arvopl@...> wrote:


Arvo W0VRA
 

On Wed, Jun 27, 2018 at 07:28 am, Jack Purdum wrote:
Is the fan quiet, or does the rcvr pick it up?
The fan is aurally quiet enough, but the case resonates a tad with it, so you can hear it.  If I wanted to do some vibration isolation and case panel damping work I could probably make it unnoticeable.

I have not noticed any noise on RX, but I'll do some fiddling to see if it gets picked up.  Any ideas for a good test?  I suppose I could use the RSP1A to look for its signal?

Doug W
 

I was in a hurry when I put my fan in so I went with this one https://www.digikey.com/product-detail/en/sunon-fans/HA60251V4-1000U-A99/259-1793-ND/6198731 and spent about as much for the grate as your fan cost.  Spending $6 on that fan felt almost extravagant but it is silent at least to my ear.  I don't have a good way to test for interference but I don't see anything different on the WSJT waterfall or hear any noise on my speaker which as all I have to go by.


--
www.bitxmap.com

Arvo W0VRA
 

On Wed, Jun 27, 2018 at 08:04 am, Doug W wrote:
...and spent about as much for the grate as your fan cost.
Haha, I keep sticking my finger in the fan so I'm waiting for this:

https://www.ebay.com/itm/2-Pcs-Dustproof-Dust-Filter-Guard-Grill-Cover-for-50mm-PC-Case-Fan-E5O8/282946981964

 

If the fan is generating RF noise,  that can often be cured but putting ferrite beads on both of the leads as close to the body of the fan as practical.
RF has a way of sneaking around on DC power leads if you are not careful. 

Cheers

Michael VE3WMB

Jack, W8TEE
 

Yep. I already bought some for that very purpose!

Jack, W8TEE

On Wednesday, June 27, 2018, 11:31:30 AM EDT, Michael Babineau <mbabineau.ve3wmb@...> wrote:


If the fan is generating RF noise,  that can often be cured but putting ferrite beads on both of the leads as close to the body of the fan as practical.
RF has a way of sneaking around on DC power leads if you are not careful. 

Cheers

Michael VE3WMB

Arvo W0VRA
 

On Wed, Jun 27, 2018 at 08:31 am, Michael Babineau wrote:
If the fan is generating RF noise
Why not wire the fan into the TX power circuit so the fan is on only during TX?

Jack, W8TEE
 

Good idea! See...that's why I'm not an EE kind of guy!

Jack, W8TEE

On Wednesday, June 27, 2018, 9:20:00 PM EDT, Arvo KD9HLC via Groups.Io <arvopl@...> wrote:


On Wed, Jun 27, 2018 at 08:31 am, Michael Babineau wrote:
If the fan is generating RF noise
Why not wire the fan into the TX power circuit so the fan is on only during TX?

Tim Gorman
 

You could always go to the hardware store and get some heavy duty
screen wire, cut a grill out, and attach it with the same screws you
use on the fan.

They even make a black screen just for keeping dogs and cats from
scratching it and tearing it. Doggone strong. That's what I've used for
a speaker grill.

tim ab0wr

On Wed, 27 Jun 2018 08:24:44 -0700
"Arvo KD9HLC via Groups.Io" <arvopl=yahoo.com@groups.io> wrote:

On Wed, Jun 27, 2018 at 08:04 am, Doug W wrote:


...and spent about as much for the grate as your fan cost.
Haha, I keep sticking my finger in the fan so I'm waiting for this:

https://www.ebay.com/itm/2-Pcs-Dustproof-Dust-Filter-Guard-Grill-Cover-for-50mm-PC-Case-Fan-E5O8/282946981964


Arvo W0VRA
 

On Wed, Jun 27, 2018 at 08:12 pm, Tim Gorman wrote:
attach it with the same screws you use on the fan.
Good idea, but I hot glued the fan to the case.  Even cheaper than screws.  I could hot glue a piece of screen to it, too.

Besides, my local hardware store wanted 13¢ for one piece of 3mm nut!  They'd probably want twice that for 4 in² of screen!

Today I'll be looking over the schematic for a 12V connection that's on during TX that doesn't use the PA supply voltage.

Arvo W0VRA
 

On Wed, Jun 27, 2018 at 06:57 pm, Jack Purdum wrote:
Good idea! See...that's why I'm not an EE kind of guy!
Well, I kinda am an EE kind of guy, kinda, so I should probably fire myself for not thinking about it in the first place!

It was easy enough to find a place for +12V on TX, namely pin 3 on U2.  I soldered the positive lead from the fan to that, and now it only comes on during TX.

  





Dennis Yancey <bigbluedry@...>
 

What size beads? And where did you get them? How should they be installed?

Vince Loschiavo
 

Arvo,
Nice catch...I'm going to move the fan supply to same spot.
Thanks
Vince
N2AIE

Vince Loschiavo
 

Jack, W8TEE
 

Nice...any more pictures??

Jack, W8TEE

On Friday, June 29, 2018, 11:32:58 AM EDT, Vince Loschiavo <vince320@...> wrote:


n4eev
 

Arv, you are one smart dude! I love your idea.

Mike N4EEV

Arv Evans
 

Mike N4EEV
Just old and remembering some of the solutions that worked in the past.
I finally got my act together and now I can't remember where I put it!  8-)
Arv  K7HKL
_._


On Sat, Jun 30, 2018 at 5:32 PM n4eev <luv.myipad3@...> wrote:
Arv, you are one smart dude! I love your idea.

Mike N4EEV

Lee
 

"I have not lost my mind, its backed up around here somewhere."
--
Lee - N9LO  "I Void Warranties"

 

Arvo W0VRA
 

On Sat, Jun 30, 2018 at 04:32 pm, n4eev wrote:
Arv, you are one smart dude! I love your idea.
Haha, well, there are always unforeseen complications.

On mine, when I open PTT the fan coasts down and I'm guessing acts like a little magnetic generator and puts quite the whir into the AF signal for a second or two.  I'm thinking the DC pulses produced by the freewheeling fan are of opposite polarity from the PS, so I could snub them with a diode, right?

Does sound kinda cool, though.  Maybe not as cool as a "Roger beep" and nobody else (I hope) can hear it.

That's what I get for testing the idea on WSPR with the volume all the way down.