Panoramic Spectrum Display - Cheap solutions survey - 2


Second hand boat anchors

Several HP and Tektronix models can be found on eBay and through surplus stores. A 1960's/1970's design 0-1000MHz unit in good working order will set you back 800 at least. Keep shipping costs in mind, as the "boatanchor" nickname means you can well splash another 100 for international delivery. Furthermore older units may start now experiencing trouble with the CRT and some components (capacitors).
Also double check frequency coverage, as some units covering microwaves may start at 10MHz or so, making them unsuitable for connection to the receiver IF.
AM/FM demodulation doesn't seem a common feature, while all markings and grids will allow for very accurate measures. Of course if you plan to use it for tuning RF devices you will need a tracking generator (included in some units) or a noise generator as well.
The HP141T seems very popular. It's composed of a mainframe display in which different coverage modules were fitted depending on customer requirements.
I've also seen some interesting GSM handset test equipment around 900, having not only spectrum analyzer functions, but also scope, DTMF decoding and more. Trouble, again, is coverage mostly starting at 10MHz.

new Far-East made equipment.

Atten is a very popular name here.
coverageotherprice
0-500MHzrange expanders not available800 approx
0-1050MHzAM/FM demoulation1100 approx
0-1050MHzAM/FM demod., tracking generator1500 approx

Homemade scope adapters.

This is a family of instruments born when real spectrum analyzer were totally unaffordable to hobbysts. Most solutions are built around TV and CATV tuners, making possible a huge range of customizations if you are in good terms with electronics and soldering irons. The most famous is the so-called
Poor man's spectrum analyzer. A complete kit is in the 600 region. Another option from "Kanga". Several other projects are available on the net.
A scope or a PC are used as display.

Commercial scope adapters.

I've seem some on eBay, however little information is given and prices seem to be a bit high when compared to other options.

Interfaces that will allow using a PC as test equipment.

The most famous are
Velleman's boxes: they will hook through the parallel port and transform your PC in a scope/spectrum analyzer. Frequency coverage seems good for receiver-IF connection only. I didn't find a suitable solution because I'm using a laptop that doesn't sport a parallel port and I'm not ready to dive into another USB-adapter nightmare again.

Software Defined Radios.

We're talking again about hooking to the receiver's IF.
Software defined radios are normally able to plot and record a slice of spectrum about 150kHz wide in real time, while wider ranger can be displayed with delays by some models.
Several options available, the coolest toy on the market seems to be
RFSpace's SDR14. This is the only one specifically designed to work both as a receiver or a spectrum monitor in conjunction with a second radio. More details can be found on the SDR14 Yahoo Group.
Other, cheaper, options include Elad's and CiaoRadio.

TV level meters.

These are units designed for TV antenna technicians. The most common seem to be from Spanish firm
Promax. Most recent units include satellite coverage and are therefore sought after by SAT TV enthisiast and will fetch higher prices. Older units start frequency coverage at 70/80 MHz and are therefore unsuitable for receiverIF connection.
Read more in my experience.

Spectrum Display Monitors.

Purposedly built units as AOR SDU5000, SDU5500 and SDU5600.
Far less common (ie almost impossible to find in Europe) are Watkin-Johnson and Atlantic Electronics units from the 1980's.
AOR models will allow control of some top-end receivers directly from the unit.
I remember somebody complaining about a slow refresh rate on older models, but an enquiry to the
AOR 8600 Yahoo Group yielded no result.
Should you go this way, the most important difference is that at least the AOR newer units (5500 and 5600?) feature a waterfall display. This keeps a track of signals in time, yielding more signal intelligence.

Last update: 24Jul06


Panoramic Spectrum Display - Cheap solutions survey
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