On another post I asked what is the proper way to use ECSS tuning method and was surprised to get few answers. According to "passport" and a few other reviews, ECSS is the holy grail of dx'ing. As I still am a little confused as to how to use it best, I still don't know if it is that important or not? What's your take? Also:I now have some great radio's including an Icom 75 WITHOUT SYNC or Side band choice. Am I missing something? The "experts" confuse the issue talking about adjustable selectivity, AGC, BFO intensity, and sideband selection in the same breath!!! I KNOW the definition and ACTIONS of ALL of the terms used, I just don"t know the connection between all and ECSS tuning. It seems to me that SYNC is just a one touch method of ECSS..HELP LOL. Thanks in advance Marc

Find a weak AM station somewhat in the clear from QRM. Turn on the BFO and zero beat. That exercise will answer most of your concerns.

Like Jack said, try it on a weak AM station or a weak, fluttery SW station, then you'll understand the use of ECSS.

I wouldn't call it a "holy grail" of reception. ECSS is just another DX 'tool' or technique, nothing more.

What Passport was probably referring to was the ease of ECSS tuning in a particular receiver. Not all receivers make for easy ECSS tuning. If their fine tuners are fidgety, it can make tuning ECSS a bear. I have a 1970's SWL comm receiver that has a touchy fine tuner. ECSS tuning is more difficult on it than it is on several of my digital portables, which have smooth fine tuning.

If your radio doesn't have a BFO or sideband capability, you could still switch in your radio's narrow filter and tune to a weak station's lower or upper AM sideband (the one on the opposite side of the QRM). The sound would be a bit distorted, but you'd still be able to read the station. For example, if there's an extra strong station on 6000 khz and you want to read the weak station on 5995, you could switch in the narrow filter and tune the radio a few khz to the lower side of 5995.

It may sound a bit distorted because you're tuning away from the center of the carrier, where the carrier is weaker. Switching in a BFO and zero beating the signal would clear up some of the distortion -- it's like adding more carrier to the side of the station's signal, to clear up the reception a bit. That's what ECSS is.

Synchronous detection is different from sideband or ECSS. I don't know that much about it. A lot of guys that have Sony 2010's swear by it.

After posting for two weeks your answers were cogent and easily understood, thanks! Just one last clarification...Sync is automatic and ECSS manual selection of the best sideband?

For years, Sync Detection and ECSS were incorrectly described as magic bullets/holy grails of shortwave reception. People explained what it was, but could never go the step further, and explain how to use it, and the benefits of using it. I am still new to using it, as my Grundig 800 is the 1st radio I have had with Sync. I am less than impressed, despite people saying it has one of the best. I have just purchased a Sony ICF-2010, and am hoping I am not going to be disappointed again- of course, another radio where people rave about Sync. I would really hate to see what radios with inferior Sync Detectors do.

There is a collection of receiving techniques and a collection of detection methods being used somewhat interchangeably since the detection techniques developed without any agreed upon wording.

Exalted carrier detection was mentioned in some of the 1950s era communications receivers and it generally referred to just using the BFO to supplement the transmitted carrier for AM and at least some of these receivers received both sidebands when set up this way. It could help with selective fading distortion. The BFO was set to zero beat the transmitted carrier and in some cases a notch filter in the receiver was used to further attenuate the transmitted carrier so the local BFO could take over this function. More modern receivers refined this technique by phase locking the locally generated carrier oscillator to the transmitted carried making exact tuning and receiver stability less critical. The first method of EC (and ECSS) was a brute force method of overriding the transmitted carrier often with the help of the notch filter.

Hallicrafters probably did more to popularize selectable sideband for AM than any other manufacturer and it was introduced with their SX-96 and most of their later better receivers used this method (i.e. SX-100, SX-101, SX-111, SX-115, SX-117, etc.) Most of the time these receivers would use the transmitted carrier for demodulation but they could be switched to CW mode to use the BFO and thus offered exalted carrier combined with selectable sideband. The Hallicrafters selectable sideband on AM family continues to be my favorite for vintage AM ham radio operation because the selectable sideband feature works EXTREMELY well at avoiding a strong interfering station either above or below the desired station and once properly tuned sidebands can be switched instantly with no retuning needed. The 5 Khz. bandwidth on these receivers provides the same recovered audio range as a traditional AM receiver with a 10 Khz. bandpass.

People sometimes have a little initial difficulty with these sets and to get a feel for proper AM tuning turn on the BFO with pitch set to 0 and tune for zero beat, this is the proper tuning point. Turn the BFO off and choose the sideband that offers the least interference. I would have loved to have had one of these back in the days when the international broadcast areas were full. Heathkit copied the Hallicrafters approach (using high or low side injection for the final mixer to select sideband) with their RX-1 Mohawk.

I have several modern receivers with sync detectors (Grundig Satellit 700, Sony 2010, Drake R8, R8A, SW8, Eton E1XM) and with selective fading distortion they all work pretty well but none of them lock up quite rapidly enough for me to use them for amateur AM operation except under relaxed conditions. They are great for broadcast stations but with amateur radio nets and roundtables the stations are never exactly on the same frequency so there is a slight annoying loss of lock with a brief lockup delay on every new transmission. The E1XM (designed by Drake) is the best I own in this speed of lockup category but for regular use in receiving broadcast stations they all work equally well. The Satellit 700 has the well known "enhanced" bass response of many German radios and the sync detector makes that more noticeable in an undesirable way and slightly reducing the bass response in sync mode helps.

My favorite radio for vintage ham operation and general broadcast listening is my Hallicrafters SX-88. I do wish it had the rapid switch selectable sideband on AM of its later family members but with it setting the selectivity to 5 or 2.5 Khz. and offset tuning so that the carrier is just slightly down the slope on either side of the passband works very well but it isn't as convenient as flipping a switch. However the higher Q of its 50 Khz. IF transformers compared to the later Hallicrafters makes up for this inconvenience. For selective fading my first choice would be a modern sync detector, second choice would be exalted carrier of the vintage sort but for amateur communications I will take regular AM (using the transmitted carrier directly for demodulation) with the selectable sideband feature. For some reason I have never been impressed with the ECSS operation of my Drake R7 although it is otherwise a very nice receiver.

Rodger WQ9E

Y'all know you're answering a 6 year old thread? I'd bet by now the OP has moved on.

Larry

It's even older than that now, but I'm glad they responded to an old thread. Good reference material, I learned quite a bit.

When discussing information that is many decades old I for one prefer the information in a few threads instead of many. I would much rather drill down into a few threads than spend time figuring out which of several hundred threads might actually be relevant-especially as search engines continue bias towards advertisers rather than informational content.

One reason the wiki approach has become so popular is it collects information about a topic in one package instead of a "google" of individual threads.

Rodger WQ9E

But we've talked about this in more recent threads, he might as well have posted to a few month old thread than a six year old thread. Subsequent replied might have added something (though not much to the overall thread) but the pistbresuurectingbthis thread didn't add much.

I'd point out that exalted carrier may have arrived with the q-multiplier. I know soon after it's invention, it was suggested for the purpose. You can peak the carrier, to boost it, but since the q-multiplier has wide skirts, the sideband still pass, the effect giving a stronger carrier.

Michael

What is ECSS ? ? ?

- Leigh

Leigh,

The acronym is for exalted carrier single sideband or it is sometimes used as exalted carrier selectable sideband. I don't know when it first became popular but Hallicrafters mentioned it in some of their 1950s era receiver manuals. Sync detectors take this to a high form by locking onto the carrier so you don't have the issue of carefully adjusting the receiver and BFO tuning.

For ham use I am not a big fan of sync detection because even the best have some delay in phase locking to a carrier which is a problem with a fast moving roundtable; I have tried a few different receivers and external boxes and none worked well when I was trying to use them while operating as net control station for a vintage AM net. There was always a slight delay, generally with a beat note, when it tried to lock on to a new station.

At times they work very well in reducing selective fading and at other times are pretty much useless.

For me, the most effective setup for vintage AM use is one of the Hallicrafters selectable sideband receivers which allows instant switching from one sideband to another on AM to avoid interference either above or below the frequency. For ham use, selective fading generally isn't a critical issue.

Rodger WQ9E

https://swling.com/blog/2011/08/using-exalted-carrier-reception-to-tune-in-pirate-radio/


And here's a good explanation of AM Synchronous Demodulation / Detection:
https://www.radio-electronics.com/info/rf-technology-design/am-reception/synchronous-demodulator-demodulation-detector.php

I had a Ham co-worker that brought in a Car radio to work in the Cal-Lab on the night shift, He loved to listen to German Broadcasts, that included a type of what he called Diversity Detection. I had never heard that term before. His explanation was that there were two separate antennas and the radio would select the antenna within the radio that had the strongest signal to reduce the fading effect.

Just to add to the content.

OK. Thanks, guys.

I've never tried it. Always used just regular receivers until I recently got an ICOM 7610 with its marvelous SDR (software-defined radio). What a sharp, useful piece of kit.

I've worked almost 250 countries with 100 watts and a ground-mounted vertical in the back yard (ground elevation about 110 feet). Must be doing something right.

- Leigh

To put it simply: you tune the radio or comm receiver to one sideband (or one 'side') of an AM signal, switch on the SSB or BFO, and zero beat the signal until the carrier disappears.

I use it with my Airspy/SDRSharp and it indeed is very useful, especially in receiving
LF stations at 198 kHZ (BBC London) and 252 kHz (both Ireland and Algeria).
Actually using just their SSB works fine ... set to AM and find zero beat, then turn
to LSB or USB. This is not "sync".

I wrote a sync program for Gnuradio, based on an earlier program for FM stereo,
and it does indeed work just fine, but no better than the above. For ham radio exact
frequency is immaterial, unlike for music. This one needs some carrier. I have thought
several times about writing a Gnuradio program that can sync to an entirely missing DSB
carrier, but its complicated and would be a tight fit. I do have a routine that works fine
for QAM digital, or VSB TV with a notch right at the pilot carrier, but its tested only on
recorded material.

There was a modification for the R-390A to add synchronous detection; I found it in one of the message threads on the R-390A site. I haven't had time to try it yet.

Really, the "holy grail" is good audio, be it from a clearer channel (no splatter from adjacents), wider filter than generally used for DX, decent AGC (doesn't necessarily pump -- my Superadios seem to have the best for that, as well as some CXA1019 IF-chipped Sonys like the ICF-38; my Sangean 808A also has pleasant AGC).

Although most of my DXing and listening is to MW, this applies to SW too.

My old Penncrest transistor sounds great on SW through headphones, when the band is reasonably uncluttered. To me, that is the holy grail of sound. There's only so much narrow bandwidth signal I can listen to before I get listener's fatigue -- ECSS or no ECSS.

I never used SYNC on SW. Do not have a radio that has SYNC on SW.