I ordered a sample book from China.. good for experiments.

Raj

开云体育

Here's the simple calculator I've been using.??

Jim,

I've looked over that spec sheet and the only thing that tells me is that they are "Signal Relays" have gold plated contacts (all good but not unique to Axicom) ...........and the ones you ordered are?V23105A5403A201??
so the "403" means the option for a 400mW coil.? Now that is a difference because the "typical" relays have the 200mW coil option. More power means more current and probably fewer turns in the coil. Nothing tells me what they did to set themselves apart from the herd. The critical contact capacitance of 2pF and the 4pf to the coil is the same as the rest of the herd.

73 Kees K5BCQ

1206 version is available at Digikey 535-11689-1-ND

Cheers,
Jim W0CHL

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

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.

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

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)

开云体育

开云体育

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

开云体育

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?

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

开云体育

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

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

开云体育

? 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