¿ªÔÆÌåÓý

Date

Re: High Frequency Choke for Bitx40

 

I think you are looking for something like this.

For fun use the calculator on that page, enter?160 or higher bands in MHz ?along with the 12 turns of wire you link shows. Compare results with the other ferites (ones beginning with "F") to the other toroids beginning with "T".
Also, you may find something suitable in an old computer power supply if you have a bad one laying around.
Tom KF5NWC


Re: Recommended fixes on ubitx.net

 

Mr Woods,

I can't thank you enough for Ubitx.net.? It's very difficult to keep up with everything here in the groups...or find previous postings.? It's very helpfull to have it all neatly summarized over there.


Re: Harmonics and Relay Replacement

Mike Short
 

I use pliers and break the component to be removed. Once it is broken apart you can focus on removing one pin at a time. No overheating the board or pads. There is not much thermal mass to draw away heat that way.


--
Mike
AI4NS


High Frequency Choke for Bitx40

 

Hello

I'm planning to do the filtering mods for the Bitx40 described here.



The only question I have is what sort of toroid I should get.? The notes mention a High Frequency Choke, but I don't really know what that is.? Various websites mention chokes using different mixes for optimal operation at different frequencies.? Which one should I go for?? What frequency range do I need for this?

Craig (VE6TBW)


Re: Harmonics and Relay Replacement

 

¿ªÔÆÌåÓý

See the link I posted from the vender, download and study the data sheet yourself.

On Oct 12, 2018, at 7:47 PM, Kees T <windy10605@...> wrote:

Jim,

Yes, I've seen that posted by you before......but what did they do specifically for RF use ? some spacings ? shielding ? coil core material ??

I also see Axicom has 4 coil power options (like most of the other relay vendors). Which one is correct and which one did you order ?

73 Kees K5BCQ


Re: Harmonics and Relay Replacement

 

¿ªÔÆÌåÓý

I really suspect they were really careful with the dielectric properties of all the case and internal insulating material as well as coil wire routing as far away from the switching contacts as possible.?

In the original one I cut open, the coil contact wires were laid haphazardly alongside the movable switching contact. ?I don't ?want to tear up a good $2 relay just to find out whats inside. ?My spectrum analyzer results are good enough proof that Potter & Brumfield (makers of the TE Axicom relays) know what they are doing. ?P & B has been in the relay business for many years and I tend to trust their products over the cheaper stuff, especially in critical RF circuits.

I worked on some pretty exotic RF equipment for a good bit of my 20 years in the US Army and regardless of the equipment's manufacturer, most of the RF switching relays were made by P & B. ??

Jim

On Oct 12, 2018, at 7:34 PM, Kees T <windy10605@...> wrote:

Jim,

Yes, I've seen that posted by you before......but what did they do specifically for RF use ? some spacings ? shielding ? coil core material ??

73 Kees K5BCQ


Re: Harmonics and Relay Replacement

 

Jim,

Yes, I've seen that posted by you before......but what did they do specifically for RF use ? some spacings ? shielding ? coil core material ? base dielectric ? housing dielectric ?

I also see Axicom has 4 coil power options (like most of the other relay vendors). Which one is correct and which one did you order ?

73 Kees K5BCQ


Re: Harmonics and Relay Replacement

 

¿ªÔÆÌåÓý

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

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


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


Re: Simpler spur fix

 

Do you think mounting the original toroids on the bottom of the board would work?


Re: Simpler spur fix

 

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


Re: Harmonics and Relay Replacement

 

¿ªÔÆÌåÓý

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

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

?

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.

?

Jim, W0EB

?

?

?

------ Original Message ------

From: "David Posthuma" <davep@...>

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@...>

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


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


Re: Harmonics and Relay Replacement

 

¿ªÔÆÌåÓý

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 ------
From: "David Posthuma" <davep@...>
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@...>

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


--
Mike Woods
mhwoods@...


Re: Harmonics and Relay Replacement

 

¿ªÔÆÌåÓý

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

?

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.

?

Jim, W0EB

?

?

?

------ Original Message ------

From: "David Posthuma" <davep@...>

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@...>

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

 

¿ªÔÆÌåÓý

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

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


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,