N2ADR Filter Board Rev E5

[Steve Haynal]

Hi Group,

I have forked N2ADR's filter board and created a revision E5. Changes are listed below. Most of these changes are experiments in reducing the 160M power supply spurs.

* Power in has a ferrite bead FB1 footprint. Claudio experimented and recommended this.

* 2 additional capacitor foot prints for larger 22uF and 100uF filtering capacitors on power in.

* Rerouting of +3V3 power to attempt to minimize interaction with RF path.

* Optional pull-up resistor on NAND input to prevent relay chattering as reported by VK7MA.

* Cutout on PCB for edge-mount SMA connectors to be recessed. This allows for simple holes in the back panel. Recommended by W3DRK.

You can find the source files on github: https://github.com/softerhardware/Hermes-Lite2/tree/master/hardware/companions/n2adr

The updated schematic is on github: https://github.com/softerhardware/Hermes-Lite2/blob/master/hardware/companions/n2adr/n2adr.pdf

Gerber files for review are on github and attached to this post: https://github.com/softerhardware/Hermes-Lite2/blob/master/hardware/companions/n2adr/n2adr_gerber.zip

You can use free gerbv on Linux or Windows to examine gerber files: http://gerbv.geda-project.org/

I'd appreciate any review and feedback.

I'm working on an assembly BOM. My plan is to have 5 or 10 units partially assembled (all SMT parts, no through hole parts) by Elecrow or Makerfabs as an initial test, since the core design is already proven. If everything works out okay, I will order more, kit through hole parts and offer these as an add on for the current build7 group buy or for separate purchase.

73,

Steve

KF7O

[James Ahlstrom]

Hello Steve,

On Tuesday, July 3, 2018 at 1:07:28 AM UTC-4, Steve Haynal wrote:

I have forked N2ADR's filter board and created a revision E5. Changes are listed below. Most of these changes are experiments in reducing the 160M power supply spurs.

These changes all look good to me.

Jim

N2ADR 

[Steve Haynal]

Hi Jim,

I am working on the BOM for assembly in China and am having a hard time finding stock for D1 and D2, Nexperia BAS40-07,217. Is the Infineon 

BAS 40-07W H6327 an acceptable substitute? Any other recommendations?

Also, is D3 (1n4148) an optional part? I thought it was there to work around an earlier relay problem on 160M that was fixed with the NAND gate.

73,

Steve

KF7O

[James Ahlstrom]

Hello Steve,

The BAS 40-07W is not suitable because it is a SOT-343 and the pad is SOT-143. I see that the data sheet shows the same footprint for the two packages, but that is suspicious. A substitute part should have good matching (usually not specified) and a low forward drop at low (1 ma) current. The Infineon BAS4007E6327HTSA1 look good and is available at Digikey (not exactly China).

The D3 1n4148 is not optional. It snubs an inductive kick from the relay coil. Any diode would do.

Jim

N2ADR

[Steve Haynal]

Hi All,

Thanks for the updates. The N2ADR filter board is now working with my BOM database and generation scripts. I have generated an assembly BOM that includes only components to be assembled in China. See attached or at:

https://github.com/softerhardware/Hermes-Lite2/blob/master/hardware/companions/n2adr/bom/bomassembly.pdf 

The schematic is at https://github.com/softerhardware/Hermes-Lite2/blob/master/hardware/companions/n2adr/n2adr.pdf

I'd appreciate any checking of this BOM. I'm looking for alternate part numbers for parts that have just one part number if possible. Also, please check the substitution allowed column.

Note that the schematic is newer and slightly out of sync with the PCB as some connectors now begin with CN. The PCB will be updated before an order is submitted. I would like to submit an order this weekend.

73,

Steve

KF7O

[Steve Haynal]

Hi Jim,

Did you post the design files for the small PCB that shorts the pins of a female socket to connect your N2ADR filter board to the Hermes-Lite? I didn't find it anywhere and would like to have some made.

73,

Steve

KF7O

[James Ahlstrom]

Hi Steve,

The jumper board files are in http://james.ahlstrom.name/hl2filter/Header2x20.zip

Jim

[Steve Haynal]

Hi Group,

I ordered 10 partially assembled N2ADR E5 boards as a test. Including shipping, assembly, PCB and parts, it works out to $35-$38 per board. The additional through hole parts, mainly relays, cost $15 to $20 more. Once I receive the units and kit one board to know the final weight, I will order more and offer this as an add on to those who purchased build7 plus standalone to others.

You can find the E5 release on github:

https://github.com/softerhardware/Hermes-Lite2/tree/master/hardware/companions/releases/n2adr_e5

73,

Steve

KF7O

[Sven Palmersjö]

Hi Steve!

I have a interest to buy 1 pcs of this board. I have HL2b6 radio.

73 de Sven SM6FMB

[Sven Palmersjö]

Hi Steve!

Can you confirm that I am on a waitinglist for this filter?

73 De Sven SM6FMB

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[Steve Haynal]

Hi Sven,

I don't have a waiting list for the N2ADR yet. I have 10 test units under production in China. If these turn out to be okay, I will probably just take as many orders as people want and buy that many units. I expect the test units back in 2 or 3 weeks, so will let you and others know then.

73,

Steve

KF7O

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