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Bought a nice brushless silent geld fan,but was surprised to hear all the huge amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all techs Ron
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Bought a nice brushless silent geld fan,but was surprised to hear all the huge
amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all
techs Ron
I put a nice large electrolytic cap across the terminals for the fan, but I don't remember how large it was.听 I think it was probably a 1000 uF or something.听 I don't think you'll go wrong with that size or larger. 听 Tom Sevart N2UHC St. Paul, KS
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Tom I tried 100uf didn't work. I will try larger Thanks Ron
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--- In BITX20@..., Tom Sevart <n2uhc@...> wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge
amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all
techs Ron
I put a nice large electrolytic cap across the terminals for the fan, but I don't remember how large it was.听 I think it was probably a 1000 uF or something.听 I don't think you'll go wrong with that size or larger.
听
Tom Sevart N2UHC
St. Paul, KS
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Tried three 470 parallel caps still sum hum.This is 3200 rpm fan. Any more ideas? Thanks Ron
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--- In BITX20@..., "ronbaechle" <ronbaechle@...> wrote:
Tom I tried 100uf didn't work. I will try larger Thanks Ron
--- In BITX20@..., Tom Sevart <n2uhc@> wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge
amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all
techs Ron
I put a nice large electrolytic cap across the terminals for the fan, but I don't remember how large it was.听 I think it was probably a 1000 uF or something.听 I don't think you'll go wrong with that size or larger.
听
Tom Sevart N2UHC
St. Paul, KS
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Do you use same supply for receiver and fan Ron ? If yes, try different supply means different transformer w/ bypass ac capacitor in the primary winding, and good voltage regulator for fan.
If still some hum, try to supply the fan using pure dc voltage and see the result, you may take some conclusions base on this simple experiment.
Just an idea Ron.
Sudarmanta - YC1DCN
Pa-kaspa-an layauw �
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-----Original Message----- From: "ronbaechle" <ronbaechle@...> Sender: BITX20@... Date: Mon, 27 May 2013 21:38:35 To: <BITX20@...> Reply-To: BITX20@... Subject: [BITX20] Re: FAN NOISE BITX20 Tried three 470 parallel caps still sum hum.This is 3200 rpm fan. Any more ideas? Thanks Ron --- In BITX20@..., "ronbaechle" <ronbaechle@...> wrote:
Tom I tried 100uf didn't work. I will try larger Thanks Ron
--- In BITX20@..., Tom Sevart <n2uhc@> wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge
amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all
techs Ron
I put a nice large electrolytic cap across the terminals for the fan, but I don't remember how large it was.� I think it was probably a 1000 uF or something.� I don't think you'll go wrong with that size or larger.
�
Tom Sevart N2UHC
St. Paul, KS
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Ron
This being a "brushless" fan may provide insight into the problem. These
units
usually have an internal switch circuit that converts DC input into AC
for running
the no-brushes motor. Polarity switching noise may be the culprit.
<
>
< >
Some electrolytic capacitors have significant internal inductance and
thus may
not be the best thing to shunt HF signals to ground. A disk ceramic
capacitor
that has fairly low impedance at either RF or IF frequency may be more
effective
at minimizing interference from the fan. In difficult cases it may even be
necessary to design and build a band-stop filter to minimize the noise
problem.
Arv - K7HKL
_._
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On 05/27/2013 03:38 PM, ronbaechle wrote:
Tried three 470 parallel caps still sum hum.This is 3200 rpm fan. Any
more ideas? Thanks Ron
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>,
"ronbaechle" <ronbaechle@...> wrote:
Tom I tried 100uf didn't work. I will try larger Thanks Ron
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>, Tom
Sevart <n2uhc@> wrote:
Bought a nice brushless silent geld fan,but was surprised to
hear all the huge
amount of noise in receiver. Best way to clear noise, Cap? What
size? Thanks all
techs Ron
I put a nice large electrolytic cap across the terminals for the
fan, but I don't remember how large it was. I think it was probably a
1000 uF or something. I don't think you'll go wrong with that size or
larger.
Tom Sevart N2UHC
St. Paul, KS
|
Thank you gentlemen for your input.Yes same supply as radio and fan.Yes I see the problems with brushless fans.I bought several and now must experiment.The large caps worked to a point,now I will try ceramic caps. Ron
toggle quoted message
Show quoted text
--- In BITX20@..., arv <arvid.evans@...> wrote:
Ron
This being a "brushless" fan may provide insight into the problem. These
units
usually have an internal switch circuit that converts DC input into AC
for running
the no-brushes motor. Polarity switching noise may be the culprit.
<
>
< >
Some electrolytic capacitors have significant internal inductance and
thus may
not be the best thing to shunt HF signals to ground. A disk ceramic
capacitor
that has fairly low impedance at either RF or IF frequency may be more
effective
at minimizing interference from the fan. In difficult cases it may even be
necessary to design and build a band-stop filter to minimize the noise
problem.
Arv - K7HKL
_._
On 05/27/2013 03:38 PM, ronbaechle wrote:
Tried three 470 parallel caps still sum hum.This is 3200 rpm fan. Any
more ideas? Thanks Ron
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>,
"ronbaechle" <ronbaechle@> wrote:
Tom I tried 100uf didn't work. I will try larger Thanks Ron
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>, Tom
Sevart <n2uhc@> wrote:
Bought a nice brushless silent geld fan,but was surprised to
hear all the huge
amount of noise in receiver. Best way to clear noise, Cap? What
size? Thanks all
techs Ron
I put a nice large electrolytic cap across the terminals for the
fan, but I don't remember how large it was. I think it was probably a
1000 uF or something. I don't think you'll go wrong with that size or
larger.
Tom Sevart N2UHC
St. Paul, KS
[Non-text portions of this message have been removed]
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If a larger cap doesn't work, try putting an inductor in series with the fan along with the cap in parallel.听 This should eliminate any whine from the fan.
听
Tom Sevart N2UHC
St. Paul, KS
|
Why are you using a fan? It could make the vfo drift more than it should. - farhan On 5/28/13, Tom Sevart <n2uhc@...> wrote: If a larger cap doesn't work, try putting an inductor in series with the fan
along with the cap in parallel.听 This should eliminate any whine from the
fan.
Tom Sevart N2UHC
St. Paul, KS
-- Sent from my mobile device
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My IRF510 get very hot on Bitx20a to the point that I burned one up in a long transmission.Im not sure if this is normal to get that hot.So the idea was to get a brushless fan thinking it would be quieter than a brush model. Please any comments Ashhar. Ps I do have a Bitx20 ver 3 sitting here ready to build and compare. Ron
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--- In BITX20@..., Ashhar Farhan <farhanbox@...> wrote:
Why are you using a fan? It could make the vfo drift more than it should.
- farhan
On 5/28/13, Tom Sevart <n2uhc@...> wrote:
If a larger cap doesn't work, try putting an inductor in series with the fan
along with the cap in parallel.听 This should eliminate any whine from the
fan.
Tom Sevart N2UHC
St. Paul, KS
--
Sent from my mobile device
|
Ron, I hope you have adequate heat sinking on the IRF510. If it is still getting hot, there may be three reasons for it: 1. The IRF510 is oscillating. If you have an oscilloscope, can you check if the waveform is clean? If not, this is where you have to work. 2. it is drawing more current than required. How much is the idling current? It should be less than 100mA. This is the current that the IRF510 will draw when you press the transmit button without connecting the mic. 3. the IRF510 is not properly matched to the antenna and most of the power is remaining in the IRF510. In such a case, you must check your antenna and the SWR. I can't think of any other scenario. - farhan On Tue, May 28, 2013 at 10:07 AM, ronbaechle <ronbaechle@...> wrote: **
My IRF510 get very hot on Bitx20a to the point that I burned one up in a
long transmission.Im not sure if this is normal to get that hot.So the idea
was to get a brushless fan thinking it would be quieter than a brush model.
Please any comments Ashhar. Ps I do have a Bitx20 ver 3 sitting here ready
to build and compare. Ron
--- In BITX20@..., Ashhar Farhan <farhanbox@...> wrote:
Why are you using a fan? It could make the vfo drift more than it should.
- farhan
On 5/28/13, Tom Sevart <n2uhc@...> wrote:
If a larger cap doesn't work, try putting an inductor in series with
the fan
along with the cap in parallel. This should eliminate any whine from
the
fan.
Tom Sevart N2UHC
St. Paul, KS
--
Sent from my mobile device
[Non-text portions of this message have been removed]
|
Hi Ashhar I did borrow a scope and cleaned up the signal after I put in a new 510. The antenna is matched good. I will recheck current.The fan was more a precaution to install and avoid a failure. Thanks Ron
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Show quoted text
--- In BITX20@..., Ashhar Farhan <farhanbox@...> wrote:
Ron,
I hope you have adequate heat sinking on the IRF510. If it is still getting
hot, there may be three reasons for it:
1. The IRF510 is oscillating. If you have an oscilloscope, can you check if
the waveform is clean? If not, this is where you have to work.
2. it is drawing more current than required. How much is the idling
current? It should be less than 100mA. This is the current that the IRF510
will draw when you press the transmit button without connecting the mic.
3. the IRF510 is not properly matched to the antenna and most of the power
is remaining in the IRF510. In such a case, you must check your antenna and
the SWR.
I can't think of any other scenario.
- farhan
On Tue, May 28, 2013 at 10:07 AM, ronbaechle <ronbaechle@...> wrote:
**
My IRF510 get very hot on Bitx20a to the point that I burned one up in a
long transmission.Im not sure if this is normal to get that hot.So the idea
was to get a brushless fan thinking it would be quieter than a brush model.
Please any comments Ashhar. Ps I do have a Bitx20 ver 3 sitting here ready
to build and compare. Ron
--- In BITX20@..., Ashhar Farhan <farhanbox@> wrote:
Why are you using a fan? It could make the vfo drift more than it should.
- farhan
On 5/28/13, Tom Sevart <n2uhc@> wrote:
If a larger cap doesn't work, try putting an inductor in series with
the fan
along with the cap in parallel. This should eliminate any whine from
the
fan.
Tom Sevart N2UHC
St. Paul, KS
--
Sent from my mobile device
[Non-text portions of this message have been removed]
|
What kind of noise Ron?
Hash noise means you will need HF filtering. A bifilar choke + small value caps (like 10nF).
Hum means you will need magnetic shielding IMHO. Most of these fans I have seen have 3 coils on a PCB that are not shielded. I am sure the pulsating mag field extends right out of the fan at the center. Increasing the distance from your rig should reduce the noise, if this is so then you need a magnetic (iron) shield (a round plate) at the center of the fan.
Raj, vu2zap
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At 27-05-2013, you wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all techs Ron
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Hi Raj I have the fan outside the case about a foot away and the receiver is picking up a sound like a buzz from the high RPM of fan.From reading what Arv said and internet research the dc brushless motors have this problem. Im going to try some RC Filtering and IC filtering and see if that works. Thanks Ron
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--- In BITX20@..., Raj <vu2zap@...> wrote:
What kind of noise Ron?
Hash noise means you will need HF filtering. A bifilar choke + small value caps (like 10nF).
Hum means you will need magnetic shielding IMHO. Most of these fans I have seen have 3 coils on a PCB that are not shielded. I am sure the pulsating mag field extends right out of the fan at the center. Increasing the distance from your rig should reduce the noise, if this is so then you need a magnetic (iron) shield (a round plate) at the center of the fan.
Raj, vu2zap
At 27-05-2013, you wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all techs Ron
|
Ron, Try a salvage a bilfilar filter transformer from an old switch mode PS, maybe a wall wart will have one. It should be the type with two pin in and out. Feed the fan supply through that and see. You could put at 0.01 on input and out of the filter transformer. Fix this nearest to fan. Raj At 28-05-2013, you wrote:
Hi Raj I have the fan outside the case about a foot away and the receiver is picking up a sound like a buzz from the high RPM of fan.From reading what Arv said and internet research the dc brushless motors have this problem. Im going to try some RC Filtering and IC filtering and see if that works. Thanks Ron
--- In <mailto:BITX20%40yahoogroups.com>BITX20@..., Raj <vu2zap@...> wrote:
What kind of noise Ron?
Hash noise means you will need HF filtering. A bifilar choke + small value caps (like 10nF).
Hum means you will need magnetic shielding IMHO. Most of these fans I have seen have 3 coils on a PCB that are not shielded. I am sure the pulsating mag field extends right out of the fan at the center. Increasing the distance from your rig should reduce the noise, if this is so then you need a magnetic (iron) shield (a round plate) at the center of the fan.
Raj, vu2zap
At 27-05-2013, you wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all techs Ron
[Non-text portions of this message have been removed]
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I too was having trouble with fan noise. Been playing with it all week! I have an 80mm (3+ inch) 12V brushless fan. I put a 100 ohm 2W resistor in series with the fan and a 680uF cap (that's what I had in the junk box) to ground on the fan side of the resistor. No noise at all now. Fan doesn't run at full speed, but moves more than enough air for the tiny box.
--
John - WA2FZW
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You need to use inductor and 1000uF electrolytic close to fan听
--
Regards
Sarma
听
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Raj vu2zap