Topband: BOG pre amp info ?

[Don Kirk]

HI Roger,

You said "However, the circuit seems odd . . . I used transformers in and
out on my Loop Preamp, to give a match to 50 ohms."

I believe your above statement was in reference to the W7IUV preamp.  I've
measured the W7IUV preamp input and output impedances and also modeled the
W7IUV preamp using LTspice, and both methods yield input and output
impedances of close to 50 ohms.  Therefore no additional components (such
as matching transformers) are required for impedance matching purposes on
the W7IUV preamp.

Just FYI,
Don (wd8dsb)

On Mon, Nov 27, 2017 at 5:36 AM, Roger Kennedy <
roger at wessexproductions.co.uk> wrote:

>
> That's a nice cheap board, and worth using considering it has relay
> switching too . . .
>
> However, the circuit seems odd . . . I used transformers in and out on my
> Loop Preamp, to give a match to 50 ohms.
>
> Roger G3YRO
>
> ------------------------------------------------------------
> ---------------
>
> Try this guy he does good quality boards and it's easier than importing
> from
> the states,
>
> https://m.ebay.co.uk/itm/W7IUV-Beverage-preamplifier-
> PCB-for-experimenters-2
> N5109-or-DCP68-transistor-/261634019988
>
> Trevor
> EI2GLB
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>