[hpsdr] [OT] Hermes VNA calibration

[probir.cedalabz]

Hi Mike,

You may use this part # FC0603E50R0BTBST1 from Vishay available at digikey 
at USD3. This will give you a 50 ohms with 0.1% tolerance. Further, this has 
got a flat response till 20Ghz and is working with our Lunaris range of SDR 
with VNA which will be launched shortly.
Even though 20Ghz is a tall claim from the manufacturer but if it gives a 
flat response till 10Ghz - its done.

You can open a 50 ohms BNC terminator - and replace this part - this could 
be slightly challenging too because the size of this part is 0603 SMD.

Further, you should look for 50 ohms rather than 49.9 ohms as recommended by 
many or else you wont be able to get a part for flat response 20Ghz range


Best regards,
Probir Debnath

CEDA
5G-Deepa Plot # 10
I.P.EXT. Patparganj
Delhi 110092 INDIA
www.ceda-labz.com
------------------------------------


The open and shorted ones are easy.  When I calibrate with a 50
ohm load and then measure other 50 ohm loads, I get variation.

I've tried a Decibel DB4303B, Relm T44100, Bird Termaline, and
various, small BNC terminators.

Where can I find a 50 ohm precision terminator that will be flat
on HF to 50 MHz?


Mike - AA8K


------------------------------

Message: 3
Date: Fri, 10 Oct 2014 10:42:50 -0600
From: Joe Martin K5SO <k5so at valornet.com>
To: aa8k73 at gmail.com
Cc: HPSDR <hpsdr at openhpsdr.org>
Subject: Re: [hpsdr] [OT] Hermes VNA calibration
Message-ID: <40CC4573-7720-4610-93C5-A602A4E5FC35 at valornet.com>
Content-Type: text/plain; charset=windows-1252

Hi Mike,

I use the NARDA Model 370BNM 50-ohm terminator (N connector) with my HP
network analyzer/S-parameter test set;  it?s flat  over the DC-18GHz range.

73, Joe K5SO

On Oct 10, 2014, at 7:49 AM, AA8K73 GMail wrote:

> ***** High Performance Software Defined Radio Discussion List *****
>
>
> What is a good 50 ohm termination to use for Hermes VNA calibration?
>
> The open and shorted ones are easy.  When I calibrate with a 50 ohm load
> and then measure other 50 ohm loads, I get variation.
>
> I've tried a Decibel DB4303B, Relm T44100, Bird Termaline, and various,
> small BNC terminators.
>
> Where can I find a 50 ohm precision terminator that will be flat on HF to
> 50 MHz?
>
>
> Mike - AA8K


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