Welcome to Sam's Microwave Page

G4DDK  / W5DDK
Loc: JO02PA

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**Important**
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. 
I can also offer the VLNA2+ kits with male, 4 hole, connectors for the same price.

For payment, I can accept Paypal, cheque (UK bank only), or Bank Transfer.

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




vlnasmall


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.

spfamp



G4DDK2001 Source


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



WA5VJB PCB antennas
Stock is constantly changing. Please inquire for current stock position.


ANTENNA
Log periodic yagis 900 - 2600 MHz and 2 GHz to 11 GHz (Including 3400 MHz) Vivaldis 2 - 25 GHz
1296 MHz and 2.4GHz 'Big Wheel' antennas.



Contents
The UK Microwave Group
RSGB
Tech stuff
WA5VJB Antennas

About G4DDK
Links  
G4DDK Blog Spot




Change history:-


13/10/2011
VLNA70 PDF updated to issue 1B




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This page last given some TLC
13/10/2011

Page first established November 1997