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Re: FAN NOISE BITX20

 

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 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
Re: FAN NOISE BITX20

 

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
Re: FAN NOISE BITX20

 

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

--- 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]
Re: FAN NOISE BITX20

 

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]
Re: FAN NOISE BITX20

 

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.听 This should eliminate any whine from the
fan.


Tom Sevart N2UHC
St. Paul, KS

--
Sent from my mobile device
Re: FAN NOISE BITX20

 

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
Re: FAN NOISE BITX20

Tom Sevart
 

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
Re: FAN NOISE BITX20

 

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

--- 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]
Re: FAN NOISE BITX20

 

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
Re: FAN NOISE BITX20

 

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 �

-----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
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.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
Re: FAN NOISE BITX20

 

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
Re: FAN NOISE BITX20

Tom Sevart
 

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
Re: toroid wire

 

Thank you for your info Dave. My ARRL membership has been expired on 2007. Otherwise Todd kindly sent me this article in pdf format.

Sudarmanta - YC1DCN

Pa-kaspa-an layauw �

-----Original Message-----
From: "va3dln" <va3dln@...>
Sender: BITX20@...
Date: Mon, 27 May 2013 14:14:35
To: <BITX20@...>
Reply-To: BITX20@...
Subject: [BITX20] Re: toroid wire

If you are an ARRL member, log in to the website, go to the QST section, then you can search for the article.

Dave
VA3DLN

--- In BITX20@..., "sudarmanta" <sudarmantatriwidada@...> wrote:

Dear Todd,

I browsed the link twice using a handphne and got the message
" We're sorry, the page you are trying to view is not accessible.

Please press your back button to visit the previous page you were on, or go to ARRL.org's homepage"

<snip>
Re: toroid wire

 

If you are an ARRL member, log in to the website, go to the QST section, then you can search for the article.

Dave
VA3DLN

--- In BITX20@..., "sudarmanta" <sudarmantatriwidada@...> wrote:

Dear Todd,

I browsed the link twice using a handphne and got the message
" We're sorry, the page you are trying to view is not accessible.

Please press your back button to visit the previous page you were on, or go to ARRL.org's homepage"

<snip>
FAN NOISE BITX20

 

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
Re: Does it make sense? Abusing a BITX20a with a MiniVNAPro

 

Faharan and Sandeep,
more than willing to help but I do not own the right equipment for amplifiers.

Dynamic range of the MiniVNA Pro in transmission mode should be about 84dB, but without an attenuator probably I cannot do much.
I will see if I could arrange a 30dB attenuator or something like that before feeding the amplifier with the raw power of the MiniVNA Pro :)

Giuseppe Marullo
IW2JWW - JN45RQ

On 5/26/2013 10:31 AM, Ashhar Farhan wrote:
Giuseppe,
I have been wanting to get someone to test our blocks on N2PK vna. I
just acquired one, but I haven't found time to hook it up. Can you
look at the amplifiers too? Specifically, I want to know the
impedances over the entire spectrum.
- farhan

On 5/26/13, Giuseppe Marullo <giuseppe@...> wrote:
Hello,
I connected two scope probes to my MiniVNA Pro and applied them to the
un-powered BITX20a. Seems interesting.

This is the 11MHz Filter (between C53 and C89):


Center frequency of the filter should be about 11.001703MHz. Not sure
if/how to trust the reported attenuation on the skirt.

I have calibrated the VNA using the probes "against" each
other(transmission mode) and against a 50Ohm dummy load(reflection mode).

I applied the same method on the RF Filter, and I discovered that
probably L4 needs adjustment (1 turn more?) because does not cover up to
half of the 20m band.

This is the flattest response I was able to achieve, too low in
frequency (the markers are the band edges):


Didn't expect too much from the experiment (impedance mismatch at
minimum), but it seems to work, what do you think?

Giuseppe Marullo
IW2JWW - JN45RQ
Re: Does it make sense? Abusing a BITX20a with a MiniVNAPro

 

Me too curious, about the amplification impedances...

Not only over the entire spectrum, but for diffrent Classes verses VDD too...

On 26/05/2013, Ashhar Farhan <farhanbox@...> wrote:
Giuseppe,
I have been wanting to get someone to test our blocks on N2PK vna. I
just acquired one, but I haven't found time to hook it up. Can you
look at the amplifiers too? Specifically, I want to know the
impedances over the entire spectrum.
- farhan

On 5/26/13, Giuseppe Marullo <giuseppe@...> wrote:
Hello,
I connected two scope probes to my MiniVNA Pro and applied them to the
un-powered BITX20a. Seems interesting.

This is the 11MHz Filter (between C53 and C89):


Center frequency of the filter should be about 11.001703MHz. Not sure
if/how to trust the reported attenuation on the skirt.

I have calibrated the VNA using the probes "against" each
other(transmission mode) and against a 50Ohm dummy load(reflection mode).

I applied the same method on the RF Filter, and I discovered that
probably L4 needs adjustment (1 turn more?) because does not cover up to
half of the 20m band.

This is the flattest response I was able to achieve, too low in
frequency (the markers are the band edges):


Didn't expect too much from the experiment (impedance mismatch at
minimum), but it seems to work, what do you think?

Giuseppe Marullo
IW2JWW - JN45RQ




--
Sent from my mobile device

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become obsolete within a very short period of time, creating a large
surplus of unwanted electronic products.
E-waste being produced could increase by as much as 500 percent over
the next ten years as the use of electronic equipment grows.

Lack of consensus and irresponsible way to deal with reuse, recycling
causes release of toxins into the environment. whereas most of the
materials used in electronic equipment can be reclaimed, recycled,
repaired and reused to produce new products.

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entering food chain can Contaminate DNA permanently those of new born.

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Please encourage recycling or reuse of E-waste.

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Re: Does it make sense? Abusing a BITX20a with a MiniVNAPro

 

Giuseppe,
I have been wanting to get someone to test our blocks on N2PK vna. I
just acquired one, but I haven't found time to hook it up. Can you
look at the amplifiers too? Specifically, I want to know the
impedances over the entire spectrum.
- farhan

On 5/26/13, Giuseppe Marullo <giuseppe@...> wrote:
Hello,
I connected two scope probes to my MiniVNA Pro and applied them to the
un-powered BITX20a. Seems interesting.

This is the 11MHz Filter (between C53 and C89):


Center frequency of the filter should be about 11.001703MHz. Not sure
if/how to trust the reported attenuation on the skirt.

I have calibrated the VNA using the probes "against" each
other(transmission mode) and against a 50Ohm dummy load(reflection mode).

I applied the same method on the RF Filter, and I discovered that
probably L4 needs adjustment (1 turn more?) because does not cover up to
half of the 20m band.

This is the flattest response I was able to achieve, too low in
frequency (the markers are the band edges):


Didn't expect too much from the experiment (impedance mismatch at
minimum), but it seems to work, what do you think?

Giuseppe Marullo
IW2JWW - JN45RQ




--
Sent from my mobile device
Does it make sense? Abusing a BITX20a with a MiniVNAPro

 

Hello,
I connected two scope probes to my MiniVNA Pro and applied them to the un-powered BITX20a. Seems interesting.

This is the 11MHz Filter (between C53 and C89):


Center frequency of the filter should be about 11.001703MHz. Not sure if/how to trust the reported attenuation on the skirt.

I have calibrated the VNA using the probes "against" each other(transmission mode) and against a 50Ohm dummy load(reflection mode).

I applied the same method on the RF Filter, and I discovered that probably L4 needs adjustment (1 turn more?) because does not cover up to half of the 20m band.

This is the flattest response I was able to achieve, too low in frequency (the markers are the band edges):


Didn't expect too much from the experiment (impedance mismatch at minimum), but it seems to work, what do you think?

Giuseppe Marullo
IW2JWW - JN45RQ
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