The AM Forum

Enjoy working AM with my Jupiter when I can. A while back, Don was telling me about synchronous AM detection, which has caused me to do a bit of digging on the subject. I see that Flex and Elecraft have now added SAM, which makes me wonder... Anyone here have any observations on one vs. the other. I am curious how they compare, both on TX and RX.

Thanks and 73,

Allen
K4XXG

Allen

Actually, to phrase the question you need to ask Flex, Elecraft & Sherwood SE3.  I'd be interested in any input with those three Synch Am modes.  I have the Flex and the SE3 and it's night and day during the night when there is deep selective fading.  Did I miss anything?

Al

Hi Allen, and welcome to the board.

There are a lot of radios with synchronous detection these days, from the lowly Grundig G-3 to the "soft rock" series, to some high dollar SDRs.  You may want to consider whether you want a standalone receiver or a transceiver with SAM.

I've been recorded on the Flex 1000 and Flex 5000 with SAM and the quality is very, very close to what I obtain right off the modulation monitor in the room.  I have not yet received a sound file from reception of my station on the Elecraft SAM to compare.

On the other question:

I also have made recordings of transmitted signals from those two SDRs, as well as of the Elecraft, and in my opinion the Flex transmitted audio is easier to adjust and has the greater potential for high quality than the Elecraft.

The Elecraft, on its own, has transmitted audio that sounds very good -- better than most "stock" amateur transmitters, both vintage and new.  But that audio is not as good as the Yaesu FT1000MP.

Al,

Good point; I would be interested in how both rigs compare to the Sherwood.  But by the time I added it to the Jupiter (assuming it is possible), I figured it would be less to just get a Flex 5000 or a K3 and have it all-in-one.

Paul,

Thanks for the insight. I had found a link elsewhere on the forum that noted some less-than-satisfactory Tx on AM with the K3.

TNX,

Allen

Not a scientific analysis, but look here http://amfone.net/Amforum/index.php?topic=30673.0 (first post and scroll down to the Rig Types) of rigs used during the recent 2012 AM transmitter rally. Flex radios were prominent but no K3's listed.

Paul,

    Maybe you are thinking of the FT1000D?

Heya Dave, I don't know how the "D" sounds unmodified.
Y'all have worked yer magic on every one of them I've ever heard on AM.

I do know that the 1000MP sounds great transmitting on AM, based on menu settings, no mods, and probably a good mic.

And the receiver has synchronous detection. Not sure it has an adequate bandpass, however.

http://www.hamelectronics.com/k1deu/pages/ham/transceivers/pages/ft-1000/ft-1000_index.html

Nah. W3DUQ had the earliest one I heard working up to standards on AM. Bill put a lot of work into that.

You should have heard Chuck's.

It seemed to keep QRM off to the sides away fairly well.

The one we used at Alpine is the same one Steve has now. That only had minimal mods and IIRC he had problems driving the audio as delivered.

Im thinking about a new radio but the K3 is not on the list. They are not an easy radio to listen to for a long time.

What about the Flex 5000A and the FT DX 5000 series? Has SDR matured enough or will todays purchase be obsolete next year?

Carl

I sit in front of computers (four at this point) all day for a living; There's no way I'm letting one into my ham shack. 8)

I don't know much about the stock 1000 or 1000D but if the stock MP is like the MP Mk V stock, there's a 6 kc wide Murata ceramic filter in there at the 455 kc stage that is inserted (only) for AM and it makes the rig pretty much sound like a Traffic Information Station.   The built-in mic preamp does the usual Yaesu thing with attenuating a range of frequencies starting at around 200 hz and working down because it was primarily designed for contesters and dx chasers.   But, deal with the filter and bypass the mic preamp and it's not bad if you can perform your own external processing.

However, (and this is a pretty big however) the MP Mk V has a big problem with carrier output migration on AM.  Not sure if the older MP or 1000D do it but the Mk V's carrier power slowly drifts up or down over the duration of a transmission; I am told it is a known design defect in the rig.   It's pretty annoying and a major motivation for moving to a plate modulated rig for me.

As for the anecdotal "bad" reports on the K3 -- perhaps one needs to consider that any radio (including the Flex which is so highly worshipped) can be adjusted quite nicely to sound like sh*t on AM.  The K3 will generate excellent AM if you EQ the thing properly and don't try to drive it with a Heil HC-4 :)   Of course, it isn't a zero to daylight BC transmitter, either.

Grant/NQ5T

One only has to make a single negative comment, no matter how minor, on the K3 forum and the attack dogs come out en masse.
Its more a cult following to deceive themselves to believe a US built rig is superior to the Japanese. None is perfect and the K3 has had a long list of problems that have been mostly....but not all... addressed. So have most all high end contenders.

This can be a problem on several of the transceivers. Some people had this problem on the FT-101s, other not. I see a little carrier level drift on my FT-1000D but it is so small as to not be a problem.

VW bypassed the FT-1000D AM filter on TX and I changed out a couple of caps and now feed the audio to the stage right before the balanced mixer. It couldn't be easier and the audio response is easily in excess of 10 kHz on the high end.

Reading Allen's first post I think he is asking for performance report of the AM Synch detector in several radios.

AL mentioned it was like night and day between a Flex and an SE3.
For $600 the Sherwood better shine!!!
I'm somewhat satisfied with my Flex 1000 and SAM. I have only experienced that and I don't know no better.
Don made comments that the Sherwood was like heaven and superior audio on AM.

The Sherwood is nice but expensive and in my opinion, Not worth the money. Entire receivers are in this price range.  Consider you can get a quicksilver SDR for this money.

I do have the ESP AM sync. Its $80 and works ok.  For the money, You cant go wrong here. 

I also own a SDR reciever with ECSS.  Exalted Carrier selectable side band AM.  It works nicely and you can choose which sideband to listen to with AM sync running. You can watch the receiver track. The soft66lc2 reciever is $100 and comes built  The software is free. 

I am working on a setup that will interface the Reciever into my station behind my icom 756 pro.  This way, Both icom and the SDR will receive at the same time through a mini circiuts splitter and a TR switch with a Receiver guard in front of the SDR. 

Some HF rigs have a TR switch built in and you can hook the SDR right to the rig.  The Icom does not. I am told most kenwoods and some yaesu's do have this option.

The advantage here is to use the icom as normal but have a RX/TX band scope with the HDSR software. Or I can turn the icom down and use the SDR as my receiver for hifi AM listening.  With ECSS and with the waterfall and multi notch, I can tune out the SSb'rs that try to ruin our fun.  If they are on LSB on 80 meters, I simply click that Sideband off and use USB in the AM mode. Poof, They are gone.

This solution is cheap. The SDR reciever is on Ebay for $100.  If your radio has an IF output, you are in biz.  Just hook the IF to the SDR with a homemade attenuator to match the level and your all set.  My icom does not and I do not want to open an expensive radio and go hacking so I am going to have to build an interface box.

If you want top notch performance, you can get a better SDR but I never found that I was wanting more performance. The Soft66lc2 work great, has plenty of gain and really sounds nice. My only wish is an RF gain control which you do not have.  Dennis gave me a small 50 ohm variable attenuator that works perfectly.

As for the comments on transievers on AM, They all can be made to sound decent. The K3 is the worst of the bunch.  Its a CW rig that they put SSB into, then AM.  Not a single elecraft engineer even thought anyone would ever push the AM button. Neat radio for the CW operator.

The FT1000D is a great one for AM.  I fed outboard audio into the back panel, EQ'd the rig and then ran it into various HF amplifers using a Scope to set the output. I got Very good reports consistantly. I got all the way out to 7K without modification.  I ran a sweep of the rig many times. 

FT101 is a no brainer. Here you can get BC transmit audio quality, 150% modulation and it still uses tubes.  Probably the best AM Transciever ever. Problem is you need to find a good one or learn the ins and outs of the 101.  They are favorite to CB'ers and often times have been Beaten down for the past 40 years

At one time, (maybe it is still like this but I don't know because I quit reading it a few years ago) the Ten Tec reflector was like that.  Post any complaint or negative comment on the Orion or Omni 6 (or anything else they made) and fanatics would go berserk.  I used to think this was a weird Ten Tec phenomenon but since I have learned Collins and Drake have these types so I'm not that surprised Elecraft does too. 

That's interesting--I used to think the problem with mine had to do with load Z problems but it does it into a Bird DL--I suspect the problem has to do with the way the rig limits the PA with the typical scheme of an output coupler generating a feedback voltage to a VCA at a low level driver stage to work the the ALC and control output.  It works for SSB and CW but not as well for AM.  The fix would be a complete redesign of the way the rig controls output and they don't want to be bothered for the .01% of customers who use it for AM.  Anyway, I'm only guessing--the problem may be something else. 

Those VW mods are basically what I did with my 1000MP Mk V.  I have been told Yaesu solved the carrier drift problem (or it just happened to go away with the new design) with the FT2000 which is completely DSP. 

 I'm not surprised about the Elecraft and CW ops--I think all the hams I know who have an Elecraft are all CW ops.  That was the status of Ten Tec for a long time.   They were a CW company--all the hams there were CW ops, and CW was where they excelled.  I guess that's not a long term good business strategy because now they are "The SSB Company."  Anyway the Omni 6 I have is a pretty good CW rig.   Too bad all this new stuff is a PITA to service.   

I will definitely look at the ESP unit.  Something I can try "some time this year" is much better than "maybe one day".

Thanks,

Allen

Hi Allen,

I can't comment on the K3 or Sherwood synch detectors, but you can take a look at two examples below of what I hear while receiving with the PowerSDR synchronous detector. The first recording of Chuck was made during a period of deep fades. The synch detector seems to handle conditions like that quite well.

Both stations were received with my Flex 5000A using the PowerSDR Synchronous Detector. K1KW and W1MPY, who are heard in the videos, are using Flex 5000A transceivers. The ability to set your AM bandwidth to anything between 0kc and 40kc on transmit and flat audio from 20cps to 20,000cps kind of sets the Flex apart from other multi-mode rigs in production at this time. Also, the ability to generate asymmetrical audio that exhibits very impressive positive peaks, which both Chuck and Bill do very nicely, sets the Flex apart from many other multi-mode rigs currently in production. I believe the HPSDR stuff will do exactly the same thing for less money and those guys are usually far less smug than Flex owners.

K1KW - Chuck transmitting with this Flex 5000A  - http://youtu.be/V9NkPXOFRmw

W1MPY - Bill transmitting with his Flex 5000A -   http://youtu.be/46Ni8lE9470

73,

Rob W1AEX

A national logo on the Flex software screen?  Really?  I mean really???  KAW MAWN.

C

Hmmm...

How about a Collins-Flex? How's that for the ultimate in smugness???

:)

LOL. Hahaha.  Thats like the other day, I saw a Nissan Sentra with BMW badges up front and on the trunk. 

C

Selective Fading sticks out like a sore thumb when listening to music. Voice transmissions, it is hardly noticeable.
Listening to WBCQ, I hear extreme selective fading at times. And there can be many seconds where the maximum distortion of the audio stays. I can see it in the waveform display on the 'scope. Like sky wave and ground wave just perfectly aligned for max distortion.

Fred

Using what??

Regarding the K3 on AM transmit,

I have been very disappointed in the K3  in AM transmit ... historically,  the Tx BW has been limited to 6Kc,  which is not so pleasant to listen to.  In Rx,  the 13 Kc filter may be selected if installed.

Perhaps this limited Tx BW has been addressed recently. Only about  one of the many K3s that I've heard on AM sounded fairly good.  The rest of them at the very best sounded like cordelss telephones.  Some of them had far too much bass boost,  which created very muffled,  bordering on unintelligable audio.

Very disappointing in a modern, mostly SDR-type rig

Think that the K3 IS a much better CW rig, than phone rig,  even still,  altho,  Elecraft did get the SSB Tx audio figured out after 12-18 months.

It is possible that Paul has heard K3s operated by some who are more interested in tweaking the K3 for all that it is worth (on AM),  than is my experience.

Have tried lobbying Ele to allow the use of the 13 Kc filter for AM Tx,  but to my knowledge,  still,  no joy.   Vic

Using no SAM on the Flex or R390A.
When using the Flex SAM on any station the effects from the selective fading are greatly reduced, not entirely gone. As long as I see what looks like a wave floating through the modulation I can hear the phasing sound.

http://www.youtube.com/watch?v=V9NkPXOFRmw

If you look long enough you can see modulation floating. But the distortion was undetectable in the presentation.

Thanks for all the replies. It looks like there may be a Flex in my future (once I get the funding figured out ;)).

73,

Allen

hey Allen
There are always reasonable deals on-line (possibly AMFONE, For-Sale,,,QTH.com or eHam classifieds) that folks upgrade from a FLEX 1000 to 5000. Or just give up and want to sell lot, stock, and barrel.

Computers are not the friendliest things, but people complicate things with THEIR way and the Flex radio will not work.
I have always found solutions at the Flex web site. I got the whole ball-o-wax working. Ham Radio Deluxe, Digital modes............no extra wires or outboard stuff...all interfaces done inside the computer...........NICE!
With all do respect to Elecraft. That was designed to be a top notch CW radio. DX-peditions love those radios for the performance.
I bought their XG-2 RF calibrator and was very impressed. Shudda bought the full blown XG-3 and had a nice sig gen in the palm of my hand, instead of this boatanchor Marconi thing.
sorry for rambling........too much coffee
Fred

Thanks, Fred.

I certainly agree with the notion that we, as operators, often either over-tinker trying to fix something that ain't broke; or under-tinker by not learning what makes a particular rig work, and deciding it must be junk.  I am confident a K3 can be setup to do an excellent job (as can my Ten Tec, for that matter) with some OTA assistance from other AM'ers, but there is a wealth of examples online of the Flex on AM, both Tx and Ex, and plenty of resources available on how to set it up. Perhaps as important is the number of ops that are well-versed in "iron"  that have added the Flex as an addition to their stations.

I would love to have the brain, time and money to be talking on and about Johnsons, Nationals, etc., but at the end of the day, the fascination with AM is much more about the quality of the operators, conversations, and audio (in that order) than how it is being accomplished. I do like nostalgia, but I mainly want to hear you better, then hopefully meme you hearing me less difficult.

73,

Allen

Allen,

Just as an item of interest, I did work a K3 on AM the other night while chatting with Steve - K1REX on 160 meters. You can take a look and listen here:

http://youtu.be/iN0ddKdKcvc

The K3 sounds fine on AM and certainly rises above many other multi-mode rigs with the AM mode. I'll let you draw your own conclusions about how it stacks up with the Flex 5000.

73,

Rob W1AEX

The K3 sounded very nice. Kinda like a DX100 with a D-104 mic.
The test would be a balsy voice and a Marshall microphone and some processing.
The operator sounded like he was using the stock microphone.

Fred

Thats up there with the most craptastic audio I have heard.  Space shuttle quality at best. 

Probably about like me on my Icom last week when the tube rig was down :(

Rob,

My first thought was "I really need to add another 60 feet or so to my antenna and get on 160"!

Thanks for the link. Actually, thanks for all the videos you post on your YouTube channel. It's great to hear all the various stations you record on the Flex.

Since that isn't your only rig, I am curious what your experience is with some of the same stations on other rigs (i.e. how much "good audio" is as much (or more) your receiver rather than their transmitter? ).

Thanks and 73,

Allen