The Rohde & Schwarz  Polyskop IV, also called SWOB 4, is a complete 
sweeper system for the frequency range of 100 kHz to 1000 MHz. With 
maximum sweep width, the complete range can be swept at one time. 
Has a narrow sweep mode as well: in this mode maximum sweep width is 
30 MHz, min. 150 kHz. Horizontal display (sweep time) adjustable 
between 20 ms and 2 seconds. Dynamic range 60 db. Built-in display 
with large CRT, built-in demodulator, no external accessories needed. 

The Polyskop SWOB IV is a compact two-channel sweep tester. 
It is as well suited for applications in the laboratory, in 
test and production departments as for all users who find 
most of all simple operation an important requirement besides 
large-screen display for single and high-quantity measurements. 
Recording may be performed by use of a recorder or photographic 
attachment. For the adjustment of the sweep width ,there are 
four possibilities. The total frequency range from 0.1 to 
1000MHz can be swept in a single sweep or the sweep width is 
continuously adjustable from 5 to 1000MHz for broadband 
measurements. For narrow-band operation the sweep width 
can be continuously adjusted from a maximum sweep width of
approximately 50 MHz to a minimum sweep width of approximately 
300 kHz .It is also possible to cut off sweep operation 
altogether so that a signal generator is obtained that can be 
continuously tuned through the range from 0.1 to 1000 MHz.

Pulse or line markers provide orientation along the frequency axis,
The marker amplitude or intensity being continuously adjustable. 
External markers can be fed in. At the lower screen edge, the 
individual sweep range selected is indicated by a bright-up bar on 
a scale .Sweep time can be continuously adjusted from 20 ms to 2 s.
The measurement curves are displayed on a long-persistence screen 
with a diagonal diameter of 28cm.