[Test-Equipment] LF Ailtech 7514 and noise sorce

[jeremy-ca]

Im very happy with a HP-8970A NF Meter, plus noise source, and manual I 
picked up at a bankruptcy auction for $109. It had a current cal sticker on 
the meter and source.

Search the local papers for auctions in your area, there are lots of 
bargains out there especially in 80's and some 90's equipment.

Carl
KM1H



----- Original Message ----- 
From: "Chris Trask" <christrask at earthlink.net>
To: "Discussion of Electronic Test Equipment" 
<test-equipment at mailman.qth.net>
Sent: Tuesday, December 25, 2007 12:13 PM
Subject: Re: [Test-Equipment] LF Ailtech 7514 and noise sorce


> >
>> > Ed,
>> >     What frequency range?  For HF I use a General Radio 1383 noise
>> > generator, an HP-141T spectrum analyzer, a homebrew 30dB amplifier, and
> a
>> > 3dB pad.  Works well as long as you're measuring a NF of 3dB or higher.
>> >
>> >   I have an Ailtech 75 PANFI and an Ailtech 136 precision receiver, but
> no
>> > low frequency noise source to go with them.
>> >
>>
>> 10 MHz to 10.5 GHz will work for me
>> WA3BZT
>>
>
> Ed,
>    Well, that helps define what you need to do NF testing, and that
> frequency range is not going to help you much in terms of economizing. 
> You
> can use the Ailtech 75 (as well as later models) if it has the internal
> mixer option, or with an external mixer.  That will require a fairly quiet
> signal generator for the LO.  Plus, you'll need two of the Ailtech/Eaton
> noise sources to cover that bandwidth.  You can get the Ailtech 75 fairly
> cheaply, but that generator and the two noise sources are going to cost 
> you
> a bit of $$.
>
>    The NF test set that I described earlier is fairly inexpensive, but 
> it's
> only useable to 20MHz unless I want to add a mixer and LO to the noise
> generator, then I can do 40MHz bandwidths at any centre frequency provided 
> I
> calibrate the then converted noise source so that I have the correct noise
> power density for the calculations.
>
> Chris
>
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