[Boatanchors] Spectrum Analyzer ??

[Roger Shultz]

Hi Ian,

I've used spectrum analyzers "forever" and find they are one of the most
useful pieces of gear anyone who does RF work can have. They are expensive
though, and they are delicate.

I have the Tek 7603 mainframe and the 7L12 spectrum analyzer plug-in. As I
recall I paid close to $500 for the 7L12. In my case it was in great shape
and worked on all ranges. It is very sensitive and does everything I need. 

One word of caution is that one must never connect it or any SA to a RF
source with any kind of power directly. A directional coupler or a sampling
slug must be used to prevent damage to the attenuators or front end...and
yes, I was careless and wiped one range. Fortunately the other ranges work
fine. 

The 7L12 has a mechanical frequency readout where the 7L13 and 14 have
digital readouts. This never bothered me because I wasn't expecting the SA
to be a frequency counter and if I wanted a precise marker, I could always
inject a signal to nail down the frequency of the signal I was interested
in.

The nice thing about the 7L12 is that it takes up just two slots enabling
one to use a dual trace plug-in and the SA simultaneously using the time
base with the SA. The 7L14 is too wide to do this. Another thing about the
7L12 and probably 13 and 14 is that when pulling the unit there is a detent
under the plug-in to prevent it being pulled abruptly and flying on to the
floor! If you don't know this, as I didn't, you might try to dissemble the
scope because you think it is stuck and won't come out! DUH... To get it out
only requires a gentle lifting over the hump. FWIW!

Expect to pay some money for a good one and makes sure you can check it out
to be sure it is good.

73, Roger, NJ2R

-----Original Message-----
From: boatanchors-bounces at mailman.qth.net
[mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of Ian
Sent: Thursday, March 27, 2008 10:01 AM
To: boatanchors at mailman.qth.net
Subject: [Boatanchors] Spectrum Analyzer ??

I am thinking of test equipment for use with the boatanchors and newer gear.

I recently bought a Tektronix 7000 series oscilloscope with 4 plug-ins from
an ad on Craigslist.

One of the plug-ins with the scope is a transistor curve tracer which might
be handy but I actually think a spectrum analyzer might be something I'd use
more often.

Among the plug-ins that were made for that series scope are 3 different
spectrum analyzers.  They consume varying numbers of plug-in space depending
on complexity and features.

*** Does anybody have experience with plug-in spectrum analyzers they can
share about those items, good/bad/indifferent?

Is this an option worth investigating?  However I'd suspect they may be
rarer than hen's teeth or new in the box unopened vacuum tube receivers and
transmitters.

Your thoughts and experience?

Thank you.

Ian, K6SDE




-----Original Message-----
From: boatanchors-bounces at mailman.qth.net
[mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of Mike WE0H
Sent: Thursday, March 27, 2008 5:43 AM
To: boatanchors at mailman.qth.net
Subject: Re: [Boatanchors] Check out this radio on Ebay

Patchwork final product & the eBay suckers are bidding it up...There are 
audiofools these days, now is there such thing as hamfools also?  hi hi...

Mike
WE0H


jeremy-ca wrote:
> Oh yeah, the NCX-1000. Nationals final lemon.
>
> I was on the design team for that but left National before it was 
> finished.
>
> It was the final example of Nationals big is better boatanchor 
> mentality at a time when the market wanted smaller packages.
>
> Solid state, complicated to work on, and no optional filters to at 
> least make it useable on CW.
>
> Poor dial calibration at a time when 1 Kc readout was expected in the 
> higher price range gear. Digital readout was planned but the NCX-5 
> assembly was "too expensive" and the cheap National 200 dial was used 
> as well as the flimsy 200 style cabinet.
>
> Transistor sockets made them easy to swap but gave the same 
> intermittent problems as the HRO-500.
>
> If only management had listened to the market surveys that were done, 
> listened to the engineering staff, hadnt been on the edge of 
> bankruptcy, etc, etc, it might have been a great rig. But chaos ruled, 
> engineers were bailing out regularly in frustration and it was a 
> patchwork final product.
>
> Carl
> KM1H

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