[hpsdr] Proposal for a 'low-end' RX/TX board for HPSDR

[CT1IZU]

----- Original Message -----
From: "Ray Anderson" <ray.anderson at xilinx.com>
To: <hpsdr at hpsdr.org>
Sent: Saturday, July 22, 2006 1:02 AM
Subject: Re: [hpsdr] Proposal for a 'low-end' RX/TX board for HPSDR


> ***** High Performance Software Defined Radio Discussion List *****
> I can see the argument for the front end LNA at 10 meters (or maybe even
> 15 meters), but on the bands below that I think it may actually be a
> liability unless you have an extraordinarily high IP3 for the preamp.
> While this can be done it comes at the expense of quite a bit of DC
> current. This may not be a big deal but is something to be considered.

Typicaly the LNA will take 60-80mA. Compared to what will disappear on tx
it pretty insignificant. One advantage of some amplification will be to lift
rx noise floor compared to the spurs and sprogs from the LO and DIG inside
the enclosure!

Ulrich suggested I think the BFG591 as a SMD alternative to the 2N5109 for
mixers and amp. Maybe the part would go well either in a Norton
configuration or the Mahkinson (N6NWP) MRF586 push pull pre-amp.

Shel CT1IZU
















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