Forums :: NEW! Web Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Oct Sat 23, 2021 1:18 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 3 posts ] 
Author Message
 Post subject: Synch Detectors Demystified!
PostPosted: Sep Mon 27, 2021 2:31 pm 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 2871
Location: Erie, Pa.
Great article that explains what synch detectors are, and what they can and cannot do.

The following paragraph is an EXCERPT from the "Shortwave Listening Post" article -


"Can sync detectors recover weak signals at all?
First off, all sync detectors can improve the signal-to-noise ratio a little, the “selectable sideband” variety often changes the filter and less bandwidth means better SNR, on top of that they let you select the sideband that’s least affected by noise or adjacent channel splatter, so the combined efforts of filtering and sideband selection can already improve weak signal reception. Removing selective fading distortion on top of that can make that a “magic button” indeed! Except…since everything changes constantly on shortwave, it can turn into the opposite seconds or minutes later, when the station decides to deliver less than the minimum required signal to keep the sync detector locked onto the carrier. In theory, the “true” sync detector doesn’t even need a carrier but so far I haven’t met an actual implementation that is capable of riding out a “carrierless” period enough to not wander off frequency. So moderately weak signals, actually affected by selective fading can reliably benefit from a sync detector. Absolute grassroots signals: not so much."


https://swling.com/blog/2021/09/guest-p ... sh-course/

(END OF EXCERPT)


Much more in the article, including waterfalls with explanations of multipath distortion, etc., and audio demonstrations of synch detectors effect.

I found this interesting and informative, and hope others will as well.

Cool to actually see and hear an explanation.

_________________
"Invisible airwaves crackle with life
Bright antenna bristle with the energy"


Top
 Profile  
 
 Post subject: Re: Synch Detectors Demystified!
PostPosted: Sep Mon 27, 2021 7:23 pm 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 5749
Location: Littleton, MA
Dalton wrote:
n theory, the “true” sync detector doesn’t even need a carrier but so far I haven’t met an actual implementation that is capable of riding out a “carrierless” period enough to not wander off frequency.

The Sony 2010 has a true Costas loop synchronous detector, so it does not require the carrier at all.

_________________
Steve Byan https://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: Synch Detectors Demystified!
PostPosted: Sep Tue 28, 2021 1:32 am 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 2871
Location: Erie, Pa.
stevebyan wrote:
Dalton wrote:
n theory, the “true” sync detector doesn’t even need a carrier but so far I haven’t met an actual implementation that is capable of riding out a “carrierless” period enough to not wander off frequency.

The Sony 2010 has a true Costas loop synchronous detector, so it does not require the carrier at all.

The article does mention the 2010's detector beingcdescribed as "legendary" by many! :D

_________________
"Invisible airwaves crackle with life
Bright antenna bristle with the energy"


Top
 Profile  
 
Post New Topic Post Reply  [ 3 posts ]  Moderator: Alan Voorhees

All times are UTC [ DST ]


Who is online

Users browsing this forum: Bill Benson, reeves03, Todd and 25 guests



Search for:
Jump to:  


































Privacy Policy :: Powered by phpBB