Topband: Hi Z amplifiers for 160m

[RT Clay]

Chris,

I just finished making my own set of amplifiers derived from the YCCC design but using SMD components. I used an AD8045 (SOIC-8 size) instead of the 8055 and added a voltage regulator.

They have replaced a set of the original Hi-Z amps (the ones in the black mini-boxes with metal covers) in my hexagonal array. I don't have a way to directly compare the performance of the new amps with the old ones, but so far they seem to work well.

Tor N4OGW





On Wednesday, March 11, 2020, 8:29:33 AM CDT, GEORGE WALLNER <aa7jv at atlanticbb.net> wrote: 





Chris,
Assuming a trans-impedance amplifier, "unity gain" is enough (with 
reasonable size elements). Noise and IP3 are far more important. Lightning 
and surge immunity are also important. Also, isolate the amp from common 
mode noise travelling on the feed-line. Filter the power supply well. Use an 
F connector (a high quality one that can be torqued.)
GL and 73,
George,
AA7JV/C6AGU

On Wed, 11 Mar 2020 11:33:34 +0000
  Chris Moulding <chrism at crosscountrywireless.net> wrote:
> As well as being a radio amateur (G4HYG) I also run a small business designing and making radio equipment (Cross Country Wireless).
>
> Recently I've been asked by a radio contest group to see if I can redesign the YCCC Hi Z amplifier using modern components and using similar mounting arrangements to our Loop Antenna Amplifier.
>
> The first prototype using surface mount components is working well.
>
> So far I've not build an array of antennas but that will come later when the production boards arrive.
>
> The prototype uses a unity voltage gain amplifier and a BNC connector.
>
> I've a couple of questions for others on the list with experience of running vertical receive arrays:
>
> Is a unity voltage gain amplifier OK or do you think it needs more gain for long coax runs?
>
> At present I'm using a BNC male connector for the output. Would an F type connector be more compatible with existing antenna arrays.
>
> 73, Chris G4HYG
>
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