Re: Harmonics and Relay Replacement
Kees, The Axicom relays were designed specifically for RF use and were made with RF isolation in mind where the original relays have almost no RF isolation between contacts, armature & coil because they were simply designed as power switching relays in and absolutely NO thought given to them being used in RF applications. ?I believe I've stated this several times in my other posts.
W0EB
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On Oct 12, 2018, at 7:25 PM, Kees T < windy10605@...> wrote: I think it's great to discover, but I would still like to see WHY the Axicom relays fix the problem and some data plots with and without. There has to be a reason other than the coil being on top of the contacts.??
73 Kees K5BCQ
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Re: Harmonics and Relay Replacement
I think it's great to discover, but I would still like to see WHY the Axicom relays fix the problem and some data plots with and without. There has to be a reason other than the coil being on top of the contacts.??
73 Kees K5BCQ
|
Do you think mounting the original toroids on the bottom of the board would work?
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Been looking around for the 1210 680nh inductors?and cannot find a source yet. I noticed some suppliers only sell in very large quantities like 2000. So has anyone found a source yet or if so would be willing to sell a few to us who want them. Just putting it out there for consideration. Please pm me to make arrangements. 73 n7hwr
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Re: Harmonics and Relay Replacement
Top IMO. ?Bottom actually degraded things on MY board. ?Probably need a few more people to test tis before a cull consensus can be reached.
Jim
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On Oct 12, 2018, at 4:34 PM, David Posthuma < davep@...> wrote: Jim: ? I have built everything in my shack including an Elecraft K2 (I was a beta tester for the 100-watt linear amp), auto-tuner, and other smaller projects. So, I am fairly comfortable, but putting them in is far easier than getting them out¡a lesson learned from too much previous experience. ? What is the consensus, solder the relays on top or on bottom of the board? ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? ? ? will get you the relays at the cheapest price in the USA that I know of ?They even have free overnight shipping. ? NO absolutely do NOT use a PC oven. ?You must use a solder sucker or solder braid from the underside of the board and unsolder each pin very carefully. In this case, using an oven would apply too much heat in all the wrong places with potentially disastrous results. Not knowing your electronics background/expertise, my suggestion to you if you aren't comfortable with de-soldering the relays one pin at a time, ?you might try to find someone with de-soldering experience to help you so you don't accidentally destroy your uBITX PC board. ------ Original Message ------ Sent: 10/12/2018 11:58:40 AM Subject: Re: [BITX20] Harmonics and Relay Replacement Jim: ? What are the actual part numbers of the Axion relays and where are you ordering them from? Did you need to use a PCB oven to remove the relays? What was your technique? I¡¯m sorry if these topics were already addressed and I missed it. ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? ? I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board. ?We have 2.8 and 5" displays running nicely with released software and instructions for them. ?The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio. I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand. ?I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ? One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring. ?It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays. ------ Original Message ------ Sent: 10/12/2018 9:45:08 AM Subject: Re: [BITX20] Harmonics and Relay Replacement Good Morning Jim,
Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
<image001.png>
Comments:
I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
Regards,
Gary
AG5TX
|
Re: Harmonics and Relay Replacement
So, is the relay mod a sure thing? I have put off ordering the relays until somebody says it definitely works. I jumped on the 45Mhz filter bandwagon and have them all installed and working on two different uBitx's and now there is a easier mod which is okay. I would just like somebody to say 'lets do this, it works'.
Joel
N6ALT
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Recommended fixes on ubitx.net
With two simple new fixes available to address the spectral purity issues associated with the uBITx, I have been busy updating the www.ubitx.net website this morning.? This includes an update to the the warning message on the front page, clarifying the fact that simple solutions exist to spectral issues on? the strengths and weaknesses page, and the addition of a new "fix" page located here:
I have also updated the ubitx.net recommended fixes and mods page located here:
Hopefully this will encourage more people to get into the wonderful world of the uBITx, and keep the factory in peak production!
Mike ZL1AXG
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Re: Harmonics and Relay Replacement
Jim
Would you be able to take a photo of a uBITx with the new Axicom
relays in place?? It would be nice to be able to show this on
ubitx.net.?? I have ordered relays from Hong Kong, but they will
take a while to arrive ...
Vy 73 Mike ZL1AXG
On 13/10/18 6:11 AM, Jim Sheldon wrote:
?
will get you the relays at the cheapest price in the USA that I
know of ?They even have free overnight shipping. ?
NO absolutely do NOT use a PC oven. ?You must use a solder
sucker or solder braid from the underside of the board and
unsolder each pin very carefully. In this case, using an oven
would apply too much heat in all the wrong places with
potentially disastrous results.
Not knowing your electronics background/expertise, my
suggestion to you if you aren't comfortable with de-soldering
the relays one pin at a time, ?you might try to find someone
with de-soldering experience to help you so you don't
accidentally destroy your uBITX PC board.
Jim, W0EB
------ Original Message ------
Sent: 10/12/2018 11:58:40 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
Jim:
?
What are the actual part numbers of the
Axion relays and where are you ordering them from? Did you
need to use a PCB oven to remove the relays? What was your
technique? I¡¯m sorry if these topics were already
addressed and I missed it.
?
David A Posthuma, WD8PUO
1 (616)
283-7703
?
?
I
have another V4 board that I'm going to build up, but
I'm waiting on a special 3.2" Color TFT touch screen
display (NOT a Nextion) for use with the Trimuvirate
Skonk Worx "BITeensio" controller board. ?We have 2.8
and 5" displays running nicely with released software
and instructions for them. ?The 5" draws too much
current so the next is a compromise down to the 3.2"
and that will probably be our last display iteration
unless something really innovative comes out that's
larger and keeps the current draw under 200 mA so we
don't have to add heavy duty 3.3V regulators on the
BITeensio.
I've
already replaced the relays on the 3rd board with
Axions (mounted on top) and I have one more set of the
Axion relays on hand. ?I may just make up a test bed
using a V3 board I have left over and keep it open
frame with DIP sockets for the relays to make it
easier to change them if something better than the
Axion comes along. ?
One
thing the Axions seemed to help with was reduce
radiated pickup of digital noise from the controller
card & wiring. ?It may be because I replace all 5
relays, or may be because I got better solder joints
(non lead-free solder) when I replaced the relays.
------
Original Message ------
Sent:
10/12/2018 9:45:08 AM
Subject:
Re: [BITX20] Harmonics and Relay Replacement
Good
Morning Jim,
Thanks for entertaining the idea.? Your shared data
maybe useful as you have shown same board and relay
with different measured results.
For that particular board and the measurement data
you gathered, I would say the results ARE
encouraging from this viewpoint:
You have 4.5 dBc more margin to FCC spec on your
worst case data point (40m 3rd harmonic) with the
supplied data set.
Comments:
I have no measurement error / uncertainty reference
or relevant personal judgement / experience to truly
offer.
But, I would think it more difficult to accurately
measure the case of more suppression, and so the
uncertainty here would be higher.
Note that the 2nd and 3rd harmonics are swapping
(80m Top and 17m Bot)
Regards,
Gary
AG5TX
|
Re: Harmonics and Relay Replacement
Jim: ? I have built everything in my shack including an Elecraft K2 (I was a beta tester for the 100-watt linear amp), auto-tuner, and other smaller projects. So, I am fairly comfortable, but putting them in is far easier than getting them out¡a lesson learned from too much previous experience. ? What is the consensus, solder the relays on top or on bottom of the board? ? David A Posthuma, WD8PUO 1 (616) 283-7703 ?
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From: [email protected] < [email protected]> On Behalf Of Jim Sheldon Sent: Friday, October 12, 2018 1:12 PM To: [email protected]Subject: Re: [BITX20] Harmonics and Relay Replacement ? ? will get you the relays at the cheapest price in the USA that I know of ?They even have free overnight shipping. ? NO absolutely do NOT use a PC oven. ?You must use a solder sucker or solder braid from the underside of the board and unsolder each pin very carefully. In this case, using an oven would apply too much heat in all the wrong places with potentially disastrous results. Not knowing your electronics background/expertise, my suggestion to you if you aren't comfortable with de-soldering the relays one pin at a time, ?you might try to find someone with de-soldering experience to help you so you don't accidentally destroy your uBITX PC board. ------ Original Message ------ Sent: 10/12/2018 11:58:40 AM Subject: Re: [BITX20] Harmonics and Relay Replacement Jim: ? What are the actual part numbers of the Axion relays and where are you ordering them from? Did you need to use a PCB oven to remove the relays? What was your technique? I¡¯m sorry if these topics were already addressed and I missed it. ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? ? I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board. ?We have 2.8 and 5" displays running nicely with released software and instructions for them. ?The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio. I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand. ?I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ? One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring. ?It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays. ------ Original Message ------ Sent: 10/12/2018 9:45:08 AM Subject: Re: [BITX20] Harmonics and Relay Replacement Good Morning Jim,
Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
Comments:
I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
Regards,
Gary
AG5TX
|
Re: Homebrew from scratch
#ubitx
Hi Peter,
Our radio club are so impressed we have 12 members who are going to build the the uBITZ using the through hole system.
I'm sourcing components and PCB's using the gerber files. However the LPF's seem to be a plug in board similar to QRP labs LPF layout but about half their size.
Any idea are these available or do we do our own design on a home produced daughter board.
Thanks
|
Re: Harmonics and Relay Replacement
Solder braid or a precision vacuum desoldering tool should be used IMO. ?If you have a Hakko or Pace desoldering station with heated tip vacuum tool this is best. ?I have a powerful spring loaded suction desoldering tool that I use with my soldering iron to suck the melted solder from the heated terminal pads, one at a time. ?Trying to heat all the pins at once spreads the heat out over the board and can overheat things. ?These relays are through hole and not SMD devices so hot air is not the way to go when removing them.
Jim
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On Oct 12, 2018, at 12:31 PM, iz oos < and2oosiz2@...> wrote: So a rework station like the one in the picture should be avoided for removing the relays, right?
Il 12/ott/2018 19:11, "Jim Sheldon" <w0eb@...> ha scritto:
? will get you the relays at the cheapest price in the USA that I know of ?They even have free overnight shipping. ?
>
> NO absolutely do NOT use a PC oven.? You must use a solder sucker or solder braid from the underside of the board and unsolder each pin very carefully. In this case, using an oven would apply too much heat in all the wrong places with potentially disastrous results.
>
> Not knowing your electronics background/expertise, my suggestion to you if you aren't comfortable with de-soldering the relays one pin at a time, ?you might try to find someone with de-soldering experience to help you so you don't accidentally destroy your uBITX PC board.
>
> Jim, W0EB
>
>
>
> ------ Original Message ------
> From: "David Posthuma" <davep@...>
> To: [email protected]
> Sent: 10/12/2018 11:58:40 AM
> Subject: Re: [BITX20] Harmonics and Relay Replacement
>
>> Jim:
>>
>> ?
>>
>> What are the actual part numbers of the Axion relays and where are you ordering them from? Did you need to use a PCB oven to remove the relays? What was your technique? I¡¯m sorry if these topics were already addressed and I missed it.
>>
>> ?
>>
>> David A Posthuma, WD8PUO
>>
>> 1 (616) 283-7703
>>
>> ?
>>
>> From: [email protected] <[email protected]> On Behalf Of Jim Sheldon
>> Sent: Friday, October 12, 2018 11:18 AM
>> To: [email protected]
>> Subject: Re: [BITX20] Harmonics and Relay Replacement
>>
>> ?
>>
>> I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board.? We have 2.8 and 5" displays running nicely with released software and instructions for them.? The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio.
>>
>> ?
>>
>> I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand.? I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ?
>>
>> ?
>>
>> One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring.? It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays.
>>
>> ?
>>
>> Jim -- W0EB
>>
>> ?
>>
>> ------ Original Message ------
>>
>> From: "Gary Anderson" <gary.ag5tx@...>
>>
>> To: [email protected]
>>
>> Sent: 10/12/2018 9:45:08 AM
>>
>> Subject: Re: [BITX20] Harmonics and Relay Replacement
>>
>> ?
>
>
>>>
>>> Good Morning Jim,
>>> Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
>>> For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
>>> You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
>>>
>>>
>>>
>>> Comments:
>>> I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
>>> But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
>>> Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
>>>
>>> Regards,
>>> Gary
>>> AG5TX
>
<IMG_20181012_192537-1.jpg>
|
Re: Harmonics and Relay Replacement
So a rework station like the one in the picture should be avoided for removing the relays, right?
Il 12/ott/2018 19:11, "Jim Sheldon" <w0eb@...> ha scritto:
? will get you the relays at the cheapest price in the USA that I know of ?They even have free overnight shipping. ?
>
> NO absolutely do NOT use a PC oven.? You must use a solder sucker or solder braid from the underside of the board and unsolder each pin very carefully. In this case, using an oven would apply too much heat in all the wrong places with potentially disastrous results.
>
> Not knowing your electronics background/expertise, my suggestion to you if you aren't comfortable with de-soldering the relays one pin at a time, ?you might try to find someone with de-soldering experience to help you so you don't accidentally destroy your uBITX PC board.
>
> Jim, W0EB
>
>
>
> ------ Original Message ------
> From: "David Posthuma" < davep@...>
> To: [email protected]
> Sent: 10/12/2018 11:58:40 AM
> Subject: Re: [BITX20] Harmonics and Relay Replacement
>
>> Jim:
>>
>> ?
>>
>> What are the actual part numbers of the Axion relays and where are you ordering them from? Did you need to use a PCB oven to remove the relays? What was your technique? I¡¯m sorry if these topics were already addressed and I missed it.
>>
>> ?
>>
>> David A Posthuma, WD8PUO
>>
>> 1 (616) 283-7703
>>
>> ?
>>
>> From: [email protected] < [email protected]> On Behalf Of Jim Sheldon
>> Sent: Friday, October 12, 2018 11:18 AM
>> To: [email protected]
>> Subject: Re: [BITX20] Harmonics and Relay Replacement
>>
>> ?
>>
>> I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board.? We have 2.8 and 5" displays running nicely with released software and instructions for them.? The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio.
>>
>> ?
>>
>> I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand.? I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ?
>>
>> ?
>>
>> One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring.? It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays.
>>
>> ?
>>
>> Jim -- W0EB
>>
>> ?
>>
>> ------ Original Message ------
>>
>> From: "Gary Anderson" < gary.ag5tx@...>
>>
>> To: [email protected]
>>
>> Sent: 10/12/2018 9:45:08 AM
>>
>> Subject: Re: [BITX20] Harmonics and Relay Replacement
>>
>> ?
>
>
>>>
>>> Good Morning Jim,
>>> Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
>>> For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
>>> You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
>>>
>>>
>>>
>>> Comments:
>>> I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
>>> But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
>>> Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
>>>
>>> Regards,
>>> Gary
>>> AG5TX
>
|
Re: Harmonics and Relay Replacement
I've never taken apart one of the relays that the uBitx comes with.
But might be possible to grind off the plastic cover with a dremel tool first,
then pluck the pins out one at a time with a needle nose pliers
while heating that pin with a soldering iron, as Jim suggests.
Another option is a hot air gun.??
I've got a 250 Watt heat gun built specifically for electronics,
but a $20 hot air embossing tool off amazon would work about as well.
Suspend the board in some sort of vice, cover the bottom of the board with tin foil
except for the area you want to heat, then play the gun?under the relays while
gently tugging at each relay from the top.
Downside is that nearby parts may be damaged by the heat, or simply fall off the board
Upside is that the uBitx has no surface mount parts on the bottom,
so if you keep the board level the other parts should not be disturbed.
Though the plastic on the antenna connector might droop a bit.
Jerry, KE7ER
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Show quoted text
On Fri, Oct 12, 2018 at 10:11 AM, Jim Sheldon wrote:
my suggestion to you if you aren't comfortable with de-soldering the relays one pin at a time,
|
Re: Harmonics and Relay Replacement
? will get you the relays at the cheapest price in the USA that I know of ?They even have free overnight shipping. ?
NO absolutely do NOT use a PC oven. ?You must use a solder sucker or solder braid from the underside of the board and unsolder each pin very carefully. In this case, using an oven would apply too much heat in all the wrong places with potentially disastrous results.
Not knowing your electronics background/expertise, my suggestion to you if you aren't comfortable with de-soldering the relays one pin at a time, ?you might try to find someone with de-soldering experience to help you so you don't accidentally destroy your uBITX PC board.
Jim, W0EB
------ Original Message ------
Sent: 10/12/2018 11:58:40 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
Jim: ? What are the actual part numbers of the Axion relays and where are you ordering them from? Did you need to use a PCB oven to remove the relays? What was your technique? I¡¯m sorry if these topics were already addressed and I missed it. ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? ? I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board. ?We have 2.8 and 5" displays running nicely with released software and instructions for them. ?The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio. I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand. ?I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ? One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring. ?It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays. ------ Original Message ------ Sent: 10/12/2018 9:45:08 AM Subject: Re: [BITX20] Harmonics and Relay Replacement Good Morning Jim,
Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
Comments:
I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
Regards,
Gary
AG5TX
|
Re: Harmonics and Relay Replacement
Jim: ? What are the actual part numbers of the Axion relays and where are you ordering them from? Did you need to use a PCB oven to remove the relays? What was your technique? I¡¯m sorry if these topics were already addressed and I missed it. ? David A Posthuma, WD8PUO 1 (616) 283-7703 ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Jim Sheldon Sent: Friday, October 12, 2018 11:18 AM To: [email protected]Subject: Re: [BITX20] Harmonics and Relay Replacement ? I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board. ?We have 2.8 and 5" displays running nicely with released software and instructions for them. ?The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio. I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand. ?I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ? One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring. ?It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays. ------ Original Message ------ Sent: 10/12/2018 9:45:08 AM Subject: Re: [BITX20] Harmonics and Relay Replacement Good Morning Jim,
Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
Comments:
I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
Regards,
Gary
AG5TX
|
In post? ? ? /g/BITX20/message/60519Lawrence Galea pointed out a Hong Kong source for Axicom relays at $0.98 USD for quantity 1, $0.60 USD for quantity 1000.? If those are genuine, or perform as well as genuine, that might be a good source for HFSignals. Jerry
On Fri, Oct 12, 2018 at 06:47 AM, Raj vu2zap wrote:
The Axicom relays cost me about 5$ landed and taxed.. I am only going to change KT1,2,3 but in
production the cost has to be kept down in true BITX spirit.
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Re: Harmonics and Relay Replacement
I have another V4 board that I'm going to build up, but I'm waiting on a special 3.2" Color TFT touch screen display (NOT a Nextion) for use with the Trimuvirate Skonk Worx "BITeensio" controller board. ?We have 2.8 and 5" displays running nicely with released software and instructions for them. ?The 5" draws too much current so the next is a compromise down to the 3.2" and that will probably be our last display iteration unless something really innovative comes out that's larger and keeps the current draw under 200 mA so we don't have to add heavy duty 3.3V regulators on the BITeensio.
I've already replaced the relays on the 3rd board with Axions (mounted on top) and I have one more set of the Axion relays on hand. ?I may just make up a test bed using a V3 board I have left over and keep it open frame with DIP sockets for the relays to make it easier to change them if something better than the Axion comes along. ?
One thing the Axions seemed to help with was reduce radiated pickup of digital noise from the controller card & wiring. ?It may be because I replace all 5 relays, or may be because I got better solder joints (non lead-free solder) when I replaced the relays.
Jim -- W0EB
------ Original Message ------
Sent: 10/12/2018 9:45:08 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
Good Morning Jim,
Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results.
For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint:
You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.
Comments:
I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer.
But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher.
Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot)
Regards,
Gary
AG5TX
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Re: Harmonics and Relay Replacement
Great find, Sarma, as the world continues to look into this problem.
I'll run a test later today with the 1mH inductor isolation of the relay coils and then see the effect of adding a 10nF capacitor across the coil. May be dependent on how the relay contact wiring is configured and what is on each armature. I wouldn't think there is a radiated problem between relays as he implies .....conducted, yes.
73 Kees K5BCQ?
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Re: Harmonics and Relay Replacement
Good Morning Jim, Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results. For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint: You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.  Comments: I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer. But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher. Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot) Regards, Gary AG5TX
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Re: Harmonics and Relay Replacement
Thanks for those pictures, Sarma. To me, that seems to indicate even closer coupling from the relay armature to the coil. Bad for RF.
73 Kees K5BCQ
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Jim Sheldon
Joel Caulkins/N6ALT
David Posthuma
