Re: Topband: 9 circle RX array combiner board

[K9FD <merv.k9fd@gmail.com>]

Many of those Chinese ones are plain junk,   if you measure them they re 
no where close to a
good 5109.    They just silk screen the number on the top of "generic" 
parts.
If you use them test them before putting them in use,  will save a lot 
of trouble shooting time.
I bought a supply from Mouser a month or two ago,  they had some on 
order,  probably all gone
by now as the word gets around.

73 Merv K9FD
> 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@shaw.ca>
> To: "Richard (Rick) Karlquist" <richard@karlquist.com>
> Cc: "Topband" <topband@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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