Topics

Expert 2K-FA generates Hash Noise

Steve Mollman
 

My Expert Amp 2K-FA (Serial No. 131200258) generates a low grade hash noise when it is put into the “Operate” mode. 
While I can live with in most conditions but when trying to work a weak signal DX it will sometimes completely obliterate the DX’s signal.  This seems to be worse on 12  Meters (not sure about 10 Meters as there is little activity these days).

For a ground I have ¾” braid from the amp bonded to the station ground and have placed multiple ferrite chokes on all of the lines to and from the amp. All to no avail!

It appears that others have commented on this problem. Does anyone know what causes this hash and more important how to eliminate it.

The station rig is an Elecraft K3.

Steve
KD9HL

Torsten - DL9GTB
 

Hi Steve,

I have exactly the same problem with my 1.3K. The problem occurs but only at certain frequencies.

73 de Torsten - DL9GTB

Ignacy Misztal
 

2k-fa has only a single toroid on the PS inside. I looped the power cable 3 times over a large 31 type toroid, and the noise is way down.

You may try to fit an extra toroid inside. But space is tight. 
  
Ignacy, NO9E

John AC4CA
 

I, too, installed a large Type-31 torroid external my 2K-FA, as close to the cabinet as possible. It is the largest clamp-on "mix" torroid KF7P (MetalWerks) sells, like ~$15. http://kf7p.com/KF7P/Ferrite_chokes.html I could only get one "turn" of the huge 220VAC power cord though the torroid.

Haven't had any recent noticeable problem with this damnable hash noise on the bands where it was noticeable before (17M and up). I wish my memory were good enough to tell you the situation eased after adding the torroid. I 'think" it did. I agree with Ignacy, though, just put one on, in any case.

Am sending Steve a photo of it separately, since I can't find instrux on adding photo to the "Photos" folder for the group.

John/AC4CA

Steve Mollman
 

I have attempted to research this and have found that the problem is fairly commo, not only with the 2K-FA, but other model Expert amps and dates back several years. Since it is quite evident that this  exists in several SPE amps I have got to wonder why SPE hasn't reacted with a fix. I have the problem on 15 meters thru 6 meters.

There seems to be several schools of thought as to the cause:

1. It is caused by the fans.  I couldn't determine from reading most posts whether the writers were commenting on noisy airflow or the fans were generating RFI.

David-VK4WR suggested changing the fan option from "Normal" to "Quiet".  I did that and at least on the initial test it seems to have reduced the RF Hash considerably!  Not entirely gone but greatly reduced. (see Page 26 of the Manual)

2. Power Supply design.

This seems to be the most popular idea for the source. 

VK3TZ-Tony  commented that he thought it was the power supply. He made reference to an amp that he had built using a similar power supply from the same manufacturer (Meanwell) and that he cleaned it up with multiple toroids and disk ceramic capacitors on the 48 volt DC output.  Ignacy- NO9E notes that there is only one torroid on the output of the power supply.  Hmm!  A design deficiency?

Ignacy- NO9E and John-AC4CA suggested installing a large Type 31 torroid on the 220 V power cord as close to the cabinet as possible.  Not having such an animal handy I used a old TV Deflection Yoke ferrite core with five turns (as many as I could get on it).  It didn't help. I then added  three clamp on type torroids to that.  Still no success. I have no idea as to what mix was used to make the yoke ferrite so that is still a wild card.  In the meantime I will order a proper Type 31 torroid.

Again, Istill have to wonder why SPE hasn't reacted to this problem.

Steve-KD9HL


---In Expertamp@..., <john@...> wrote :

I, too, installed a large Type-31 torroid external my 2K-FA, as close to the cabinet as possible. It is the largest clamp-on "mix" torroid KF7P (MetalWerks) sells, like ~$15. http://kf7p.com/KF7P/Ferrite_chokes.html I could only get one "turn" of the huge 220VAC power cord though the torroid.

Haven't had any recent noticeable problem with this damnable hash noise on the bands where it was noticeable before (17M and up). I wish my memory were good enough to tell you the situation eased after adding the torroid. I 'think" it did. I agree with Ignacy, though, just put one on, in any case.

Am sending Steve a photo of it separately, since I can't find instrux on adding photo to the "Photos" folder for the group.

John/AC4CA

Pete W1RM
 

I’m new to this group.  I’ve had my Expert 2K for less than a year and have not heard anything that I would call hash or any sort of interference from the amp.

 

I’m curious as to the age of the amps that folks are saying generates hash.  Also, has anyone contacted Bob, W5UQ about this?

 

 

Pete, W1RM

W1RM@...

 

From: Expertamp@... [mailto:Expertamp@...]
Sent: Friday, March 16, 2018 10:30 AM
To: Expertamp@...
Subject: [Expertamp] Re: Expert 2K-FA generates Hash Noise

 

 

I have attempted to research this and have found that the problem is fairly commo, not only with the 2K-FA, but other model Expert amps and dates back several years. Since it is quite evident that this  exists in several SPE amps I have got to wonder why SPE hasn't reacted with a fix. I have the problem on 15 meters thru 6 meters.

There seems to be several schools of thought as to the cause:

1. It is caused by the fans.  I couldn't determine from reading most posts whether the writers were commenting on noisy airflow or the fans were generating RFI.

David-VK4WR suggested changing the fan option from "Normal" to "Quiet".  I did that and at least on the initial test it seems to have reduced the RF Hash considerably!  Not entirely gone but greatly reduced. (see Page 26 of the Manual)

2. Power Supply design.

This seems to be the most popular idea for the source. 

VK3TZ-Tony  commented that he thought it was the power supply. He made reference to an amp that he had built using a similar power supply from the same manufacturer (Meanwell) and that he cleaned it up with multiple toroids and disk ceramic capacitors on the 48 volt DC output.  Ignacy- NO9E notes that there is only one torroid on the output of the power supply.  Hmm!  A design deficiency?

Ignacy- NO9E and John-AC4CA suggested installing a large Type 31 torroid on the 220 V power cord as close to the cabinet as possible.  Not having such an animal handy I used a old TV Deflection Yoke ferrite core with five turns (as many as I could get on it).  It didn't help. I then added  three clamp on type torroids to that.  Still no success. I have no idea as to what mix was used to make the yoke ferrite so that is still a wild card.  In the meantime I will order a proper Type 31 torroid.

Again, Istill have to wonder why SPE hasn't reacted to this problem.

Steve-KD9HL



---In Expertamp@..., <john@...> wrote :

I, too, installed a large Type-31 torroid external my 2K-FA, as close to the cabinet as possible. It is the largest clamp-on "mix" torroid KF7P (MetalWerks) sells, like ~$15. http://kf7p.com/KF7P/Ferrite_chokes.html I could only get one "turn" of the huge 220VAC power cord though the torroid.

Haven't had any recent noticeable problem with this damnable hash noise on the bands where it was noticeable before (17M and up). I wish my memory were good enough to tell you the situation eased after adding the torroid. I 'think" it did. I agree with Ignacy, though, just put one on, in any case.

Am sending Steve a photo of it separately, since I can't find instrux on adding photo to the "Photos" folder for the group.

John/AC4CA

Dennis Edey
 



ISOLATOR ISOLATOR ISOLATOR ISOLATOR,
DXE  MAXI CORE is Preference,

Remove all antenna coax feeds and REMOVE earth from unit in question,

THEN CHECK for hash,
9 from 10,  crap is coming in on Coax's and Earth bus

there has been instances of Once Coax & earth removed, HASH disappeared,
if the guys that this happened to,  are on this reflector
PLEASE put up your hand,


Cheers
Dennis vk4sx

Bad news and BS travels 1000 Times faster then the facts,



On 17/03/2018 12:30 AM, kd9hl@... [Expertamp] wrote:
 

I have attempted to research this and have found that the problem is fairly commo, not only with the 2K-FA, but other model Expert amps and dates back several years. Since it is quite evident that this  exists in several SPE amps I have got to wonder why SPE hasn't reacted with a fix. I have the problem on 15 meters thru 6 meters.

There seems to be several schools of thought as to the cause:

1. It is caused by the fans.  I couldn't determine from reading most posts whether the writers were commenting on noisy airflow or the fans were generating RFI.

David-VK4WR suggested changing the fan option from "Normal" to "Quiet".  I did that and at least on the initial test it seems to have reduced the RF Hash considerably!  Not entirely gone but greatly reduced. (see Page 26 of the Manual)

2. Power Supply design.

This seems to be the most popular idea for the source. 

VK3TZ-Tony  commented that he thought it was the power supply. He made reference to an amp that he had built using a similar power supply from the same manufacturer (Meanwell) and that he cleaned it up with multiple toroids and disk ceramic capacitors on the 48 volt DC output.  Ignacy- NO9E notes that there is only one torroid on the output of the power supply.  Hmm!  A design deficiency?

Ignacy- NO9E and John-AC4CA suggested installing a large Type 31 torroid on the 220 V power cord as close to the cabinet as possible.  Not having such an animal handy I used a old TV Deflection Yoke ferrite core with five turns (as many as I could get on it).  It didn't help. I then added  three clamp on type torroids to that.  Still no success. I have no idea as to what mix was used to make the yoke ferrite so that is still a wild card.  In the meantime I will order a proper Type 31 torroid.

Again, Istill have to wonder why SPE hasn't reacted to this problem.

Steve-KD9HL



---In Expertamp@..., wrote :

I, too, installed a large Type-31 torroid external my 2K-FA, as close to the cabinet as possible. It is the largest clamp-on "mix" torroid KF7P (MetalWerks) sells, like ~$15. http://kf7p.com/KF7P/Ferrite_chokes.html I could only get one "turn" of the huge 220VAC power cord though the torroid.

Haven't had any recent noticeable problem with this damnable hash noise on the bands where it was noticeable before (17M and up). I wish my memory were good enough to tell you the situation eased after adding the torroid. I 'think" it did. I agree with Ignacy, though, just put one on, in any case.

Am sending Steve a photo of it separately, since I can't find instrux on adding photo to the "Photos" folder for the group.

John/AC4CA


Virus-free. www.avast.com

Ignacy Misztal
 

The Experts have a commercial switching PS. They generates hash. Whether you will hear it depends on how close your antenna, how balanced,  and how noisy your location is. I have a feeling that 1.3k-fa is less noisy than 2k-fa.

Not all toroids work well. I use type 31.

If you have invested in the Expert, invest in an antenna analyzer. Fa-VA4 is pretty cheap and very accurate. It will show you how effective  a toroid is at a particular frequency.    I think one needs at least 500 Ohms. 

Ignacy, NO9E  

Matt Brosious <bluewaterpro@...>
 

I have 2 Expert 2Kfa and no noise at all on my HP Spectrum Analyzer. Perhaps you have an older or malfunctioning unit. Mine are 2016 vintage. 

On Fri, Mar 16, 2018 at 7:20 PM, 'Tusk ...' tuskyone@... [Expertamp]
wrote:
 



ISOLATOR ISOLATOR ISOLATOR ISOLATOR,
DXE  MAXI CORE is Preference,

Remove all antenna coax feeds and REMOVE earth from unit in question,

THEN CHECK for hash,
9 from 10,  crap is coming in on Coax's and Earth bus

there has been instances of Once Coax & earth removed, HASH disappeared,
if the guys that this happened to,  are on this reflector
PLEASE put up your hand,


Cheers
Dennis vk4sx

Bad news and BS travels 1000 Times faster then the facts,



On 17/03/2018 12:30 AM, kd9hl@... [Expertamp] wrote:
 

I have attempted to research this and have found that the problem is fairly commo, not only with the 2K-FA, but other model Expert amps and dates back several years. Since it is quite evident that this  exists in several SPE amps I have got to wonder why SPE hasn't reacted with a fix. I have the problem on 15 meters thru 6 meters.

There seems to be several schools of thought as to the cause:

1. It is caused by the fans.  I couldn't determine from reading most posts whether the writers were commenting on noisy airflow or the fans were generating RFI.

David-VK4WR suggested changing the fan option from "Normal" to "Quiet".  I did that and at least on the initial test it seems to have reduced the RF Hash considerably!  Not entirely gone but greatly reduced. (see Page 26 of the Manual)

2. Power Supply design.

This seems to be the most popular idea for the source. 

VK3TZ-Tony  commented that he thought it was the power supply. He made reference to an amp that he had built using a similar power supply from the same manufacturer (Meanwell) and that he cleaned it up with multiple toroids and disk ceramic capacitors on the 48 volt DC output.  Ignacy- NO9E notes that there is only one torroid on the output of the power supply.  Hmm!  A design deficiency?

Ignacy- NO9E and John-AC4CA suggested installing a large Type 31 torroid on the 220 V power cord as close to the cabinet as possible.  Not having such an animal handy I used a old TV Deflection Yoke ferrite core with five turns (as many as I could get on it).  It didn't help. I then added  three clamp on type torroids to that.  Still no success. I have no idea as to what mix was used to make the yoke ferrite so that is still a wild card.  In the meantime I will order a proper Type 31 torroid.

Again, Istill have to wonder why SPE hasn't reacted to this problem.

Steve-KD9HL



---In Expertamp@..., wrote :

I, too, installed a large Type-31 torroid external my 2K-FA, as close to the cabinet as possible. It is the largest clamp-on "mix" torroid KF7P (MetalWerks) sells, like ~$15. http://kf7p.com/KF7P/Ferrite_chokes.html I could only get one "turn" of the huge 220VAC power cord though the torroid.

Haven't had any recent noticeable problem with this damnable hash noise on the bands where it was noticeable before (17M and up). I wish my memory were good enough to tell you the situation eased after adding the torroid. I 'think" it did. I agree with Ignacy, though, just put one on, in any case.

Am sending Steve a photo of it separately, since I can't find instrux on adding photo to the "Photos" folder for the group.

John/AC4CA


altVirus-free. www.avast.com

John K9EL
 

I had some noise issues on 12 meters and above – hash type noise.  Not sure if it was from the amplifier, the 3 computers running in the shack or the 2 dozen or so other devices with small crappy power supplies.

 

My cables enter the house and go to a patch/grounding panel.   Then there is a 20 foot length of cable to the radio.   I found that even with the antennas disconnected at the end of the 20 foot cable, I was still picking up noise.   I realized the cable itself was acting as the antenna as the noise was generated in the shack and not being picked up externally.

 

I ordered some double shielded cable and replaced all my coax runs to the panel.   All the noise disappeared.   If you are using very old RG type coax, it may be worth doing the same test I did.

 

I have a 1.3 and have never noticed any hash from the amplifier.

 

73, John K9EL

 

From: Expertamp@... [mailto:Expertamp@...]
Sent: Friday, March 16, 2018 7:35 PM
To: Expertamp@...
Subject: [Expertamp] Re: Expert 2K-FA generates Hash Noise

 

 

The Experts have a commercial switching PS. They generates hash. Whether you will hear it depends on how close your antenna, how balanced,  and how noisy your location is. I have a feeling that 1.3k-fa is less noisy than 2k-fa.

 

Not all toroids work well. I use type 31.

 

If you have invested in the Expert, invest in an antenna analyzer. Fa-VA4 is pretty cheap and very accurate. It will show you how effective  a toroid is at a particular frequency.    I think one needs at least 500 Ohms. 

 

Ignacy, NO9E  

Ignacy Misztal
 

> I have 2 Expert 2Kfa and no noise at all on my HP Spectrum Analyzer. 
> Perhaps you have an older or malfunctioning unit. Mine are 2016 vintage. 

Mine is a 2013 model. The PS was replaced 1.5 years ago so it isn't it. But is is possible that there is an extra ferrite inside. It can be much smaller than outside since only inside wires are wound, not the thick jacket.

Ignacy, NO9E



Matt Brosious <bluewaterpro@...>
 

Mine is completely clean....



From: "no9e@... [Expertamp]"
To: Expertamp@...
Sent: Friday, March 16, 2018 10:31 PM
Subject: Re: [Expertamp] Re: Expert 2K-FA generates Hash Noise

 
> I have 2 Expert 2Kfa and no noise at all on my HP Spectrum Analyzer. 
> Perhaps you have an older or malfunctioning unit. Mine are 2016 vintage. 

Mine is a 2013 model. The PS was replaced 1.5 years ago so it isn't it. But is is possible that there is an extra ferrite inside. It can be much smaller than outside since only inside wires are wound, not the thick jacket.

Ignacy, NO9E





Max NG7M
 

Like W1RM, I haven't seen any issues with my 2K-FA related to hash when in operate mode (or otherwise).  I have had mine for just less than 1 year.  The amp has been flawless.  I would have noticed anything over the last year because I'm always looking at a 192khz spectrum display while operating any band (or zoomed in based on operating mode).  Plus, from day one I have had a 240v ICE line filter in line with the 2A-FA and a very good ground system to the line filter and amplifier as you would expect.  I think I'll throw a 2.4 inch mix 31 on the power cord this weekend.  It certainly can't hurt.

Max NG7M




http://www.nc7j.com/pa/main.php?cmd=album&var1=NG7M%2FLM-470+Tower%2FGrounding+and+Bonding%2FIn+the+Shack%2FPre-Bonding+New+2+Inch+Strap/


 

Craig Anderson <w9cla@...>
 

I have had three 2K-FA  amplifiers and none of them have exhibited the hash noise that you have described.

 

Craig W9CLA

 

From: Expertamp@... [mailto:Expertamp@...]
Sent: Saturday, March 17, 2018 4:22 PM
To: Expertamp@...
Subject: RE: [Expertamp] Re: Expert 2K-FA generates Hash Noise

 

 

Like W1RM, I haven't seen any issues with my 2K-FA related to hash when in operate mode (or otherwise).  I have had mine for just less than 1 year.  The amp has been flawless.  I would have noticed anything over the last year because I'm always looking at a 192khz spectrum display while operating any band (or zoomed in based on operating mode).  Plus, from day one I have had a 240v ICE line filter in line with the 2A-FA and a very good ground system to the line filter and amplifier as you would expect.  I think I'll throw a 2.4 inch mix 31 on the power cord this weekend.  It certainly can't hurt.

 

Max NG7M

 

 


 

http://www.nc7j.com/pa/main.php?cmd=album&var1=NG7M%2FLM-470+Tower%2FGrounding+and+Bonding%2FIn+the+Shack%2FPre-Bonding+New+2+Inch+Strap/

 

 

 

Steve Mollman
 

An update.  Taking the various suggestions I looped four turns of the 220 volt line through a type 31 donut ferrite.  No change.

There was some success though.  I put eight clip-on type 31 ferrites on the USB cable that goes from the computer to the 2K-FA.  They were placed as close as possible to the amp. This seems to have reduced the hash to a barely discernible level. I can hear it very slightly but it is not enough to register on the panadaptor.  If I wasn't listening for it I probably wouldn't notice it.

One clip-on didn't do anything. It took multiple clip-ons to start reducing the hash.  After eight of them, there was no noticeable improvement.  This equates with my past experience with clip-on ferrites.  More than one is usually needed to have any effect.

As insurance, I have placed multiple ferittes on all of the other cables that attach to the amp.

To answer some questions:

Age of amp. The amp was delivered new in April 2013.  The power supply was replaced after the original immediately failed.

Antenna Cables.  LMR-400 (Belden RF-400)

Ground System.  Four interconnected 8 foot copper coated rods driven into the earth and located 5 to 20 feet from the station. ALL of the station, including the computer and other accessories, are connected via 3/4 inch braid to a common bus. 3/4 inch braid to the ground rods.

Steve   
KD9HL




---In Expertamp@..., <kd9hl@...> wrote :

My Expert Amp 2K-FA (Serial No. 131200258) generates a low grade hash noise when it is put into the “Operate” mode. 
While I can live with in most conditions but when trying to work a weak signal DX it will sometimes completely obliterate the DX’s signal.  This seems to be worse on 12  Meters (not sure about 10 Meters as there is little activity these days).

For a ground I have ¾” braid from the amp bonded to the station ground and have placed multiple ferrite chokes on all of the lines to and from the amp. All to no avail!

It appears that others have commented on this problem. Does anyone know what causes this hash and more important how to eliminate it.

The station rig is an Elecraft K3.

Steve
KD9HL

Dennis Edey
 


Hi Steve, many instances are RFI Transfer,  SPE rectified manufacture side of minor internal gnd issue in early production, Shielded USB leads by Lindy.com. Line isolator on feed line,  + after amp, Disconnect EARTH system for test ( i have 500amp earth battery sw on gnd system for storms,)
sounds like a monitor maybe or something local,

GPU CPU etc etc

do you have a PIR Security light??
just recently I was trouble shooting an SPE / K3 install, culprit was 12VDC PIR security light, when PIT circuit was active,  LUX control was corroded, meaning PIR was ON / OFF thru the day as well.

just an idea as they throw up some garbage.

good luck

Dennis vk4sx

On 23/03/2018 1:46 AM, kd9hl@... [Expertamp] wrote:
 

An update.  Taking the various suggestions I looped four turns of the 220 volt line through a type 31 donut ferrite.  No change.

There was some success though.  I put eight clip-on type 31 ferrites on the USB cable that goes from the computer to the 2K-FA.  They were placed as close as possible to the amp. This seems to have reduced the hash to a barely discernible level. I can hear it very slightly but it is not enough to register on the panadaptor.  If I wasn't listening for it I probably wouldn't notice it.

One clip-on didn't do anything. It took multiple clip-ons to start reducing the hash.  After eight of them, there was no noticeable improvement.  This equates with my past experience with clip-on ferrites.  More than one is usually needed to have any effect.

As insurance, I have placed multiple ferittes on all of the other cables that attach to the amp.

To answer some questions:

Age of amp. The amp was delivered new in April 2013.  The power supply was replaced after the original immediately failed.

Antenna Cables.  LMR-400 (Belden RF-400)

Ground System.  Four interconnected 8 foot copper coated rods driven into the earth and located 5 to 20 feet from the station. ALL of the station, including the computer and other accessories, are connected via 3/4 inch braid to a common bus. 3/4 inch braid to the ground rods.

Steve   
KD9HL




---In Expertamp@..., wrote :

My Expert Amp 2K-FA (Serial No. 131200258) generates a low grade hash noise when it is put into the “Operate” mode. 
While I can live with in most conditions but when trying to work a weak signal DX it will sometimes completely obliterate the DX’s signal.  This seems to be worse on 12  Meters (not sure about 10 Meters as there is little activity these days).

For a ground I have ¾” braid from the amp bonded to the station ground and have placed multiple ferrite chokes on all of the lines to and from the amp. All to no avail!

It appears that others have commented on this problem. Does anyone know what causes this hash and more important how to eliminate it.

The station rig is an Elecraft K3.

Steve
KD9HL


Virus-free. www.avast.com

Allan Saul
 

Actually the 2K-FA 12m noise issue goes back to 2013. The factory and Bob was aware of the problem even back then and came up with a mod solution on the small power supply which never worked. 
Even with antennas disconnected, with the 2K in standby mode you will hear hash on 12m unless you are in Quiet mode on the fans. If you are in Normal mode (which is recommended for CW operation) then the fans are on, the power supply is generating some current and the hash is ever present as a consequence. 
I have increased the weight of my 2K considerably with a liberal application of ferrites on the internal PSU leads all to no good effect. 
There is also a strange "warbling" noise on 17m which is hard to pin down.
Eventually I just gave up and considered the 2K's benefits much outweigh its few vices
but it is annoying when trying to work a station on the limit. 

73 de Allan ZS1LS 

Ignacy Misztal
 

I wrote that 2k-fa has RFI mostly on 12 and 15m only in operate position, and that wrapping the power cord around a large type 31 ferrite a few times decerased RFI dramatically.  

Lately I found that even with wrapping there is substantial RFI on 20m. Perhaps because signal levels are low with poor propagation so that the noise is more apparent. But I also had a PS replaced. So perhaps the new PS is more noisy. 

The noise is coming form the large PS because there is no noise in standby noise. 

I hear only noise from a 2 el quad that is 35 ft up from the shack. The quad is also picking lots of other house noise. No amp noise heard with antennas far away.

One problem could be that the quad does not have a true symmetric feeding and thus picks up common noise. 

Ignacy, NO9E