Text largely copied and adapted from Alan Cordwell.

"Pulse/8 was a Decca Survey product, and another name for AccuFix, and it was in use during the 1970's through to the mid/late ‘90's. It operated in the low frequency band, and radiated a pulse transmission very similar to Loran-C. It was a hyperbolic system using time-of-flight techniques, with station identification by means of pulse pattern recognition and PRI timings. One could use Pulse/8 in a Range–Range mode providing one had an accurate frequency standard connected and associated hardware/software.

The transmitting equipment was manufactured by Megapulse Inc. and used an unusual technique of magnetic compression. The first receiver used in 1976 by the then Decca Survey was produced by Internav and called the S501. This could be set to receive three ranges and to display any two of them at one time. The next receiver to be deployed was the Mk4, designed in-house in Decca Survey it was smaller and lighter and better, it could display 3 range measurements continuously. And give output data via several parallel ports."

Shown is a Mk2 Pulse/8 receiver (Type 90080) which seems to have all the features of the MkIV except the 7 serial ports.. All were once part of Nederlandse Survey Apparaten (NeSA) from Rotterdam which later became Racal and then Thales Survey before the instrument division became Reson and then Teledyne Reson. When no longer usefull with the NeSA they arrived in the collection of Rob Berlijn (together with a number of other instruments also in my collection). When Rob passed away to early his widow donated the objects to CT-Systems who in turn, after many years of custody donated them to the exception of a few land survey instruments which are now in the collection of Nicolas de Hilster as they are more fitting in that collection. I am very happy to be able to show these as I was afraid that they had become lost to history. Thank you Rob for your foresight!

More information:

Alan Cordwell