Frequency Hopping Spread Spectrum

[Andre Kesteloot]

>
> On 12/28/13 4:27 PM, James Wolf wrote:
>> Frank,
>>
>> FH is only what it says it is, it does not refer to or define a 
>> waveform,
>> however a waveform may define FH.  SS would be complimentary to FH 
>> and is
>> used in 802.11x waveforms as well.  The early frequency hopping 
>> HaveQuick
>> radios were analog, hopped very slowly and you lost the audio in the 
>> dwell
>> time when switching to a new frequency, so there were dropouts every 
>> time it
>> changed frequencies. 

James,

If you refer to the /_ARRL Spread-Spectrum Sourcebook_/ (downloadable 
free in PDF format from the AMRAD Web-site), you will see the 
description of an early FH system that ws created by Terry Fox WB4JFI.
Chuck Phillips N4EZV(SK) and I then developed and operated a FH beacon 
in the 2-meter band.
Another beacon was put in operation in Vienna VA and was built by Dave 
Borden K8MMO(SK), Terry Fox WB4JFI, Elton Sanders WB5MMB, Hal Feinstein 
WB3KDU and Bernie
  Stuecker K4XY.
In late 1981, N4EZV and I demonstrated a FH system based on modified 
Heathkits, hopping, as I recall, at about 90 hops per second.

What we are doing now ( WB3KDU, AA4HS, myself and a few others) is just 
a continuation, but with better gear  :-)

73,
André N4ICK


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