Topband: 9 circle RX array combiner board

[donovanf at starpower.net]

There's no shortage of 2N5109s on eBay for about one dollar each 


www.ebay.com/sch/i.html?_from=R40&_nkw=2n5109&_sacat=0&_sop=15 


73 
Frank 
W3LPL 

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

From: "VE6WZ_Steve" <ve6wz at shaw.ca> 
To: "Richard (Rick) Karlquist" <richard at karlquist.com> 
Cc: "Topband" <topband at contesting.com> 
Sent: Sunday, March 1, 2020 11:56:39 PM 
Subject: Re: Topband: 9 circle RX array combiner board 

Hi Rick, 

Yes, the 2N5109s are almost un-obtainium now, but a few months ago Mouser stocked them and maybe DigiKey, but now they are out-of-stock. Even the 2N3866 substitute is hard to find. 
Over the years (2 decades) I have built at least 10 of these amps, and still have a supply of a dozen or so 2N5109 devices, and since these devices are almost indestructible, I’ll likely never run out! You are correct that this is a problem with this design. 

Thanks for the E-field amp link….nice…perhaps another project to build! 

I like KiCad a lot. super easy to learn. I had never use a PC board program, but I was able to learn KiCad from scratch in one evening! 

de steve ve6wz 



> 
> Now I know why you work stuff I can't even hear :-) 
> 
> The 2N5109 is just about extinct. Did you secure a 
> source for it before you laid out your PC board? If 
> you did, please share it with the rest of us. Most 
> people are now using substitutes for the 2N5109 with 
> varying degrees of success. Are you possibly doing 
> that? Of course those substitutes are not in a 
> hermetic metal can, so the PC board has to be laid 
> out for differently for them. 
> 
> You might want to look at these references for 
> so-called "E-field" arrays of whip antennas: 
> 
> A military design: 
> 
> https://www.dst.defence.gov.au/sites/default/files/publications/documents/DST-Group-TR-3522.pdf 
> 
> Various improvements to the above: 
> 
> http://home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf 
> 
> You also find a lot of other good stuff on Chris's site. 
> 
> They go beyond the DXE design. 
> 
> Good luck with your project. 
> 
> BTW, how do you like KICAD? I'm currently using a grandfathered 
> EAGLE 7.7 perpetual license, but "some day" I might switch to KICAD. 
> 
> 73 
> Rick N6RK 

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