G4DDK  / W5DDK
Loc: JO02PA

You have arrived at my new web host. This is the only site that will be updated for the foreseeable future.



VLNA70  PDF 1B
As published in DUBUS 3/11. The new VLNA70 is the result of a lot of work to produce a stable, repeatable 70cm low noise preamplifier using the PCB and mechanical arrangements of the well-known 23, 13 and 9cm VLNA2+ preamplifiers. The VLNA70 provides a noise figure of better than 0.4dB with a gain of 40dB. The input P1dB point is approximately -20dBm. The input return loss is approximately 10dB. With careful adjustment the input return loss can be improved to 20dB or better. Best of all, the new VLNA70 is stable in operation. It is impossible to guarantee that it is stable at all mismatch phase angles, but tests suggest that it will remain stable with most if not all current 70cm antenn designs. With 40dB gain second stage noise contribution should no longer be a problem in EME systems. For terrestrial use I recommend a 20dB attenuator at the preamplifier output. The PDF includes construction details. However, it is best to read this in conjunction with the following VLNA2+ PDF C2

In order to simplify names the VLNA preamplifiers are now all called VLNA, with the VLNA70, VLNA23, VLNA13 and VLNA9 covering the 70, 23, 13 and 9cm respectively.


VLNA PDF C2
This document now replaces the previous PDF. It incorporates all of the VLNA2+ updates for the 23, 13 and 9cm  versions of the VLNA2+
The original Issue B3 is still available here for those who need it.

VLNA kits  are £49.50 each plus postage and packaging.  For orders over £100 I recommend International Signed For service, where available.
All band kits are the same price plus postage and packaging. 

E-mail me for details. My e-mail address is near the foot of this page.
 
Link to pre-amplifier articles Includes a 'must read' by Sergie, RW3BP



New 
SPF5043Z amplifier. The SPF5043Z amplifier article appears in the July issue of Scatterpoint, the newsletter of the UK Microwave Group. This is a slightly updated version of the amplifier article including some new figures and details of the kit that is available from me. For readers in the USA, similar kits are available from WA5VJB.




G4DDK2001 Source


Thanks to the RSGB for allowing me to publish a reprint of the original G4DDK2001 Radcom Article on my web page.