Old school inversion de-scrambling device

[rf_patriot200]

I still have one of the Don Noble electronics descramblers around here somewhere ... I think they were DNE-12's in a Black and Beige case.

 

[kv5e]

Krystal Kits in Arkansas built tunable speech inversion descramblers too back in the 70s.

Tom Oberheim designed a ring modulator for Maestro:



This worked well for inversion scramblers and used a 1496 balanced modulator IC.

I remember the DoJ going after Ramsey for their descrambler kits and FM transmitters.

Slash Dot discussion of DoJ and Ramsey

 

[Ensnared]

I think Ramsey made those kits, which could also be purchased wired and in case.

I still own one. Years ago, I heard voice inversion being used near Rolla, MO. I should note this was a bit difficult to understand at times due to the electronic voice. It was weird.

 

[kc2asb]

I still own one. Years ago, I heard voice inversion being used near Rolla, MO. I should note this was a bit difficult to understand at times due to the electronic voice. It was weird.

Interesting. I thought the de-scrambler reversed the inversion and revealed the natural voice. This works differently than expectations.

 

[kv5e]

Inversion scrambler uses a four-quandrant multiplier with voice frequencies and a carrier which determines the "turnover" point of the inverted voice spectrum. Most designs have a diode ring or IC four-quadrant multiplier which should be balanced. They can have leakage when unbalanced which adds frequencies to the scrambled signal Additionally, the same waveform should be used for the carrier inputs on both ends. If the carrier waveform/frequency is different or imbalances exist in the multiplier, then the voice can be different, but understandable.