Agreed Rob.
ACSSB is nothing more than regular old SSB with a few things added. The compandering is simply speech compression on the transmit end and an equivalent expansion on the receive end to restore the dynamic range of the voice. This gives some noise reduction in the circuit. As mentioned before the SEA radios placed the pilot tone in the middle of the band pass. The other guys just inserted some carrier (as I remember) for a pilot. This has been done for many years in the marine radio service on the SSB circuits. The carrier was run at 20 db down from peak power. The repeaters were licensed with a specific ERP and height above average terrain. So combiner loss, cable loss, antenna gain and height above average terrain were all factored in to determine the power output of the repeaters. The biggest problem was the cost of the equipment. They could not get the cost down to be competitive with FM. ACSB started out on the VHF bands with a few channels placed in-between FM two way channels. The problem there was too much interference from the FM side bands that clobbered the ACSSB receivers. Being amplitude based there is no capture or limiting like there is with FM so any little noise is heard. ACSSB can have much better range than FM with a clear channel (no noise) but it is hard to find such. SEA petitioned the FCC for a portion of the 220 band to get ACSSB only channels to get away from the problems with sharing with FM on the VHF channels. It was a good thought but the equipment had other problems, mostly manufacturing at reasonable cost. 73 Gary K4FMX _____ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Robert Pease Sent: Friday, November 13, 2009 8:01 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] ACSSB Interesting thing about part 97. It is written differently than any other part of the rules. In most of the rules they tell you what you can do and if it isn't specifically spelled out then you can't do it. In part 97 it is the other way around. For the most part they tell you what you can't do. So unless it specifically says you can't so it, it is assumed ok. This was done this way to promote experimentation with new modes and new ways to use old modes. I can't speak to this mode specifically but look at it technically as in bandwidth, modulation,... The tech specs that may exclude it from use, not the name or mode itself. JMO. YMMV. Rob Sent by Good Messaging (www.good.com) -----Original Message----- From: DCFluX [mailto:dcf...@gmail.com] Sent: Thursday, November 12, 2009 09:13 PM Eastern Standard Time To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] ACSSB Could you please provide a rule number to back this up? Linear Modulation and ACSSB share 4K00J3E as the emission designator. On Thu, Nov 12, 2009 at 5:34 AM, n0fpe <n0...@cox.net> wrote: > One thing to remember. Amatuers are NOT authorized to use ACSSB above 30mhz. Please check part 97 for the exact "modes" we are able to use. > heck if we were there would be tons of ACSSB repeaters already modified into the ham band. (Yahoo! ID required) Change settings via email: Switch <mailto:repeater-builder-dig...@yahoogroups.com?subject=email%20delivery:%20 Digest> delivery to Daily Digest | Switch <mailto:repeater-builder-fullfeatu...@yahoogroups.com?subject=change%20deliv ery%20Format:%20Fully%20Featured> to Fully Featured Visit <http://groups.yahoo.com/group/Repeater-Builder;_ylc=X3oDMTJjdGcyZDNmBF9TAzk 3NDc2NTkwBGdycElkAzEwNDE2OARncnBzcElkAzE3MDUwNjMxMDgEc2VjA2Z0cgRzbGsDaHBmBHN 0aW1lAzEyNTgxMTcyMjE-> Your Group | Yahoo! Groups <http://docs.yahoo.com/info/terms/> Terms of Use | Unsubscribe <mailto:repeater-builder-unsubscr...@yahoogroups.com?subject=unsubscribe>
