Re: Harmonics and Relay Replacement


Howard Fidel
 

I got them from Digikey in 3 days. Had to order something else, so shipping charges were not an issue.

On 11/1/2018 6:01 AM, iz oos wrote:

I believe that the replacement with the Axicom relays should be a must in any case. I hope they will soon arrive... to make some rudimentary check... bought them on a non-sale price and still been waiting for weeks... seems like they sold them being short...

Il 01/nov/2018 00:03, "Gene Nitschke" <genenitschke@...> ha scritto:
>
> Sorry to ask but I been offline for a few weeks and the subject seems to have died out (after reading past posts).  So is there a final solution for the spurs/harmonics for the V3 uBitX?
>
> Axicom replacements (soldered directly to PWB)?
> Axicom replacements with SMD inductors?
> K5BCQ uBITX Relay Switched LPF/BPF board?
> I have an unbuilt V3 that I am not sure if I should even complete.  I want to be legal but do not have a lot of test equipment so verification will be difficult.
>
> Thanks,
> Gene N2IJF
>
> ________________________________
> From: BITX20@groups.io <BITX20@groups.io> on behalf of Raj vu2zap <rajendrakumargg@...>
> Sent: Thursday, October 25, 2018 12:59 AM
> To: BITX20@groups.io
>
> Subject: Re: [BITX20] Harmonics and Relay Replacement
>  
> The before relay pic has slightly degraded performance due to the relays being mounted on
> sockets. This add a few mm extra length to the leads to the contact and increases coupling!
>
> The second is Axicom soldered directly on PCB.
>
> With Axicom my boards are perfect on 40 and 80.
>
> Raj
>
> At 24-10-18, you wrote:
>>
>> That's pretty impressive, Raj.
>>
>> Jack, W8TEE
>>
>> On Wednesday, October 24, 2018, 1:06:11 AM EDT, Raj vu2zap <rajendrakumargg@...> wrote:
>>
>>
>> Jim,
>>
>> I did  not get much improvement with Axicom in a socket.. soldering directly to board made a big difference.
>> The harmonic rejection on lower bands was amazing!
>>
>> On one board only 20M is a bit off.
>>
>> Raj
>>
>> Example: the first is stock and 2nd is Axicom. The second needs to be referenced to -1db to compare to
>> first!
>>
>>  
>>  
>>
>> At 23-10-18, you wrote:
>>>
>>> No, I just used the relays.  I was looking for the simplest approach.  I have several other projects that were on hold, giving me time to try the relay swap Mike Doty originally discovered with limited but encouraging results. 
>>>
>>> I've done all I plan on doing regarding the harmonic reduction.  I shared what I found with the group, got unjustly accused of being a "phoney" and I now wash my hands of this part of the project.
>>>
>>> Back to improving the available firmware, displays and controller hardware. 
>>>
>>> Jim
>


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