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HF AM Mode


#1

Hi all,

I have been reading an article in QST magazine relating to the fun you can have on AM Mode ??!!

Is there any one out there especially chasers fancy an experiment on AM maybe on 14.286 or 7.290 or more an idea of mine 50.400??

I will alert on one of my future activations in the hope of maybe the odd S2S also on this possible not enough used mode???

73

Tony


#2

In reply to 2E0LAE:

…expect to be unpopular on busy HF bands as AM occupies twice the bandwidth of an SSB signal!

7.290MHz is outside the UK band I think.

73

Richard
G3CWI


#3

In reply to 2E0LAE:

AM = Ancient modulation. There are reasons why SSB was developed you know! I wouldn’t have thought it was the obvious 1st choice for QRP portable operators, but each to his own.

7.290

Do you have a NOV for that frequency? :wink:

However, if people want to waste bandwidth and power on AM they could at least do it properly with EL34s and a big transformer in the modulator before hitting a pair 4-125s or similar! :slight_smile:

Andy
MM0FMF


#4

In reply to G3CWI:

Hi Richard and Andy,

Yes realised after I posted that 7.290 was outside UK band Sorry !!!

I was looking at the article in QST which I realise now that its a Stateside Magazine!!!

I just like to experiment as much as possible and thought " lets see whats happens"

I know because of the nature of the mode I would only need to TX on 10 watts as the PEP would be 40 watts if used correctly which keeps me below my Maximum allowed power.

I would obviously look at listening to SSB first to ensure causing problems to a crowded band.

Maybe my suggestion was just me jumping in too quick???

Never mind

73

Tony


#5

In reply to 2E0LAE:
There is regular AM activity on 80 metres, with some operators using vintage XWD equipment, I have for instance heard R1155/T1154 units (as used in the Lancaster bomber) and 19 sets, a little drifty perhaps, but good fun and being contacted by operators with modern gear with low-level AM. There is said to be AM activity on 20 metres but I haven’t heard any yet - but I don’t infest that band very often! :wink:

SSB is a great technological advance over SSB, but AM sounds closer to BC quality and is more tolerant of mis-tuning, and after all, sails became obsolete over 100 years ago but people still sail yachts…and ride horses! There is no reason why you shouldn’t give it a go if only to say that you have experienced what ham radio sounded like fifty years ago!

73

Brian G8ADD


#6

In reply to G8ADD:

Thanks Brian for the info about 80m will now listen for the activity on AM from the shack.

I was told Amateur Radio was all about self learning and experiments, and thats my Ethos, and yes as a two year licensed operator I am still learning.

But I believe it doesnt matter how long you have been licensed,there is always something to learn?

I am not a operator who likes the idea of “5-9 bye bye” contest calls but would never interfere in what they are doing.

I love SOTA as it combines both my love of hill walking and radio, and trying something different is my idea of experimenting.

looking at the statistics,there have been 85 AM ops, is this only early on in SOTA days or recently?

best 73

Tony


#7

In reply to 2E0LAE:

looking at the statistics,there have been 85 AM ops,

Actually it’s 1 AM operation (GM8OTI to the Edinburgh .800 mafia) and 84 keying errors when people were entering their logs! :slight_smile:

Andy
MM0FMF


#8

In reply to 2E0LAE:

Hi Tony,

I believe AM is still used on 10m. Looking at the bandplan 28.32-29.20MHz is OK for QRP and shouldn’t upset too many people. I think I read somewhere there is even a regular Net somewhere in London (29.05MHz if I remember correctly).
So if you think you will find yourself in range of West Cumbria I would be willing to give AM a shot in the interests of experimentation but give me plenty of warning since I don’t have an aerial for 10m at the moment.

73,

Colin.


#9

In reply to 2E0LAE:

I’m hoping to be out & about tomorrow so will listen out for you if you want to try AM somewhere. My intended summit has a clear line of sight to NW-042 so if you are still around when I arrive at the summit we should be able to use any of the higher bands without difficulty.

I will only be running 5 Watts maximum this time though so I won’t be my usual strong signal on HF, I may even have to use CW! Gulp!

73,

Mark G0VOF


#10

In reply to G8ADD:
I came across 2 OM’s on 80m the other day. One was an ex-pat in Denmark and the other could have read the news on the Home Service. The interesting part was when they switched to their 1940s AM rigs. Being new to the 'obby, it was the first time for me hearing the same QSO on both LSB and USB just like in the diagrams in the licence course books. No pen and paper to hand or I’d have sent the gents a SWL QSL card.

David 2E0DAI


#11

The main interest in AM in ham radio circles over the last 20 years (apart from the guys who use the old restored military gear) is a bunch of guys in the USA who last sunspot cycle, used to transmit in AM on the 10m band above around 29 MHz where they wouldn’t get into bother, with the main intention of transmitting their audio in broadcast standard speech quality. In other words HiFi for radio hams. It was mainly home brew gear with big modulation transformers, special microphones and valves 1950s style (before SSB became commonplace). Their transmissions could be as much as 12 KHz wide. I recall hearing stations of similar speech quality when I took up SWLing in 1968 by listening to a top band net in Lancashure on Sunday mornings on a modified transistor radio with long wire attached. This was how I found out about ham radio.

I’m not sure if any of these AM guys are still about. You may be able to find something out by Googling the subject.

73 Phil


#12

In reply to G4OBK:

I just found this link:

http://www.w3am.com/

73 Phil


#13

In reply to 2E0LAE:

In reply to G8ADD:

Thanks Brian for the info about 80m will now listen for the activity
on AM from the shack.

Hi Tony

Quite a lot of AM activity on 3615 and 3625, and I understand
that there is also a net which operates in the region of 7145.
Well worth a listen if you like discussions on vintage equipment.

73

Dave G0ELJ


#14

In reply to 2E0DAI:

it was the first time for me hearing the same QSO on both LSB and USB

You’ve never listened to a MW broadcast radio then? :wink:

In reply to everyone:

I can understand restoring and using some old boatanchor on AM from the 40’s or 50’s on AM. You know the type of thing where the PSU is so heavy it strains the floor joists of a modern house. Restoring and using boatanchors is just as cool as restoring and driving classic cars (another of my interests). Preserving something from a bygone age for everyone to see old engineering is great. But having owned 2 classic cars (Vanden Plas 4L Rolls-Royce & Rover P5B Saloon) I can tell you the reason we don’t still make classic cars is because they’re rubbish. They don’t stop, start, drive straight, keep cool and if you have a crash then the chances that you wont loose your legs as the gearbox comes through the firewall is remote.

They’re an intellectual curiosity that has been eclipsed by better things. Just like AM. The engineer in all of us cries out “no” whenever AM is considered. Unless it’s from a restoration set of course. The fact that 75% of the output power is not used should make everyone cry. Worse, some modern solid state rigs do low level modulation AM so bad they can’t even get to 100% mod depth.

AM might sound nice and smooth but we’re not DJs, we’re simply trying to communicate. Like the HiFiSSB idiots with their racks of Behringer gear, you don’t need 12kHz of BW to be understood. People need to accept that they’re not Dink Winkerton doing the late night show on KJAZ in downtown 'Frisco “spinning cool tunes for hot nights” but some bloke in the attic/basement/spare bedroom talking about his tomatoes/hernia/carolina windom/Windows not booting/broadband not fast enough etc. etc.

So I ask everyone to come to their collective senses and stamp out this nonsense. If we don’t stop it now the next thing will be some saying they’re going to try using spark from the top of a summit and everyone else will be rushing to get their coherers set up.

Thank you, I feel better for that rant. Now I’m off up a wee hill :slight_smile:

Andy
MM0FMF


#15

In reply to MM0FMF: As CW predated AM, should we, by your logic, ditch that as well?

Dave, G6DTN (Totaly tongue-in-cheek as I try to pick calls out of the frenzy of a cw activation, before biting the bullet and following the trend)


#16

In reply to M0DFA:

Nice one, Dave!

73

Brian G8ADD


#17

In reply to M0DFA:
But then if you follow Andy’s bandwidth argument we should all only be using CW :slight_smile:

Roger G4OWG

I have only one AM chase in my log, on 2m with G6DDQ/P


#18

In reply to G4OWG:
Also FM goes back much further than people think, perhaps we should abandon that, too!

No, there has got to be a place for heritage modes so that we don’t forget our past - well, according to the bandplans CW has every place anyway! I still think it is nice to hear good AM and it needn’t be more than 6 kHz wide to sound good. Of course, that doesn’t mean I would like to hear the band full of carriers again…

73

Br5ian G8ADD


#19

In reply to G8ADD:
Of course, that doesn’t mean I

would like to hear the band full of carriers again…

Hi Brian,

Come on now, you know in your heart of hearts you would!
I’ve got my magnetic detector and rotary spark lined up,-
just waiting for my NOV to come through!!

73

Dave


#20

In reply to G0ELJ:
Did you apply for it on the basis of evaluating spread spectrum? :wink:

73

Brian G8ADD