Other SOTA sites: SOTAwatch | SOTA Home | Database | Summits | Video | Photos | Shop | Mapping | FAQs | Facebook | Contact SOTA

World Wide AM activity weekend

AM Activity weekend

If you have noticed the monthly stats showing the number of contacts logged using various modes, there is no doubt which modes are the most popular and which ones have less support. But at the bottom of the statistics table, there is always one mode in last position: AM. And sometimes the QSO count is zero!

With that in mind, as most bands permit AM operation, why not make a few contacts using AM? When? On the weekend of April 1st to 3rd. Now you might look at the 1st of April and suspect someone is pulling your leg, having a lend of you, making a joke. Not at all. We ran a one day event last year in VK and found it was a lot of fun (and most of us appreciated SSB even more afterwards). In particular on vhf bands where there was no selective fading, AM was a very nice mode to use. Those of us who remember AM on 2m and 6m will find great pleasure in returning to AM on those bands, if only briefly.

So what’s in it for you? A participation certificate will be available on application after the logs are in (details of how to apply will announced later).

Bands? Any you like.
Times? up to you on 1st, 2nd or 3rd of April 2016.
Number of contacts? at least one to qualify for the participation certificate.

Use your own judgement about which bands to operate on, taking other users, band segment usage patterns and your battery into account. AM will be somewhat more demanding in terms of power required than SSB or CW.

This event has been organised with MT approval by the VK1 and VK2 associations. All we have really done is write this flyer. The rest is up to you.

See you on the bands, on April 1-2-3, on AM.

73
Andrew
vk1da/vk2uh

I’m proud to say I was never around in those AM days. Apart from pressing the band button on the FT 857D a couple of times is there anything else anyone suggsets I need to know to use AM? Do I need to wear a tweed hat perhaps??

Compton
VK2HRX

1 Like

I’ll try to get on at a “long-path possible” time, here in Germany - I suspect conditions will need to be very good to manage an AM-AM EU-VK S2S (or even S2C) contact, but if we never try, we’ll never know! I wonder if there’s any contest on 20m on that weekend, whose operators can really appreciate our W-I-D-E signals…

Ed.

1 Like

Hi Compton,

No, just a lounge suit and Windsor knotted tie. AM chappies are an informal bunch with modest dress standards.

AM from solid state rigs doesn’t have the crispness of a plate and screen modulated valve so I may have to fire up my vintage all valve station for chasing.

73
Ron

1 Like

In CT AM day I made some contacts with the KX-3. Pretty modulation!

Actually the closest modulation I ever heard to a plate and screen modulated valve rig…

No more valve transceivers at home!

GL on VK AM day!

Actually it’s World Wide AM day. Not just VK.

Tnx for info Andy. Where can I find more info about it ?

TNX

Read the first post in this thread :smile:

Quite scarce for ww activity, I guess. :smile:

I wish you succeed.

And because the April 2nd is the Portugal SOTA National Day I will try to do some AM contacts, i e, get the best of 2 worlds!

73

Compton,

Its the mode button you need to press. Then pick up the thing on the end of the curly cord, squeeze the moving bit and talk into the grille. Your voice will come out of the speaker at the other end. I don’t know how it works but it does. And while your radio is in that mode, those funny squawking sounds are people using that new fangled ssb mode. Don’t let their funny noises put you off. call cq again.

Hope we can work sometime that weekend.

Thanks & 73

Andrew VK1DA/VK2UH

3 Likes

Ron,

At Wyong I found myself looking at a Heath DX60 with vfo and companion receiver. Sooooo tempting. But I know every capacitor would be suspect. Such nice looking gear though…

Cheers

Andrew

You will need at least another 8dB improvement in SNR - Its possible, but not on QRP…

I have been having great fun running AM in some of my recent activation’s recently.

15m has a AM allocation at the top of the band, can not recall the allocation at this precise moment. Some USA AM would be great :slight_smile: fire up them 833A modulators !

Jonathan

It’s a shame the FT290 doesn’t have AM then we could have had Vintage Electric Handbags on the AM weekend. My old FT690Mk1 did AM. I can only recall 2 AM QSOs when I had it back in the 90s. One with a local to prove it worked and one with an OZ station when there was an enormously strong SpE event on but I had worked all the LA/SM/OZ/OH stations on USB. I called on 51.500 FM and an OZ replied and we had effortless armchair copy on FM then AM. That was at least 19 years ago when I think about it.

Hi Jonathan,
I may be able to squeeze about 20w out of my small amp - that’s a 4 times improvement on the normal 5W but not 8dB. Well I was told QRP 5w + dipole on SSB wouldn’t get me an S2S contact from DL to VK, but it has done on several occasions. We can only try - it’ll be fun (and hopefully a little WARMER by then).

Ed.

Really?

For AM, only 25% of the signal is used so your 20W AM signal has the same signal power as 5W SSB.

You may respond with “but I did VK-EU S2S with 5W SBB so I’ll be OK”. A valid statement but for AM you have twice the bandwidth at the RX and therefore whilst you only use half the bandwidth for the signal you use ALL the bandwidth for the noise. So you’re still worse off with 3dB more noise for 20W AM vs 5 SSB.

This means you need 9db (theoretical) more power for the same received SNR and put into powers

5W SSB ~= 40W AM.

That doesn’t mean you shouldn’t try. It’s just significantly harder or more dependent on good conditions than the same as path on SSB.

It might be worthwhile setting up a wire V-beam or rhombic beaming appropriately. Don’t forget that with a rig with two VFO’s you can set up to receive on SSB with one and transmit with AM on the other, AM is a bit ticklish to tune as SSB but it can be done, with the benefit of reducing the noise - those Yaesu AM filters are barn door wide!

I shall be a bit of a slob, wearing carpet slippers, a dressing gown and a woolly hat!

(Not on a summit, of course - though it might be tempting!)

Brian

Good luck with the event.
Just looked at my log, last year, the last two dx contacts (Americas) on AM were on 21.432 and 29.012Mhz so if anybody visits the higher bands I will give it a chasing go.
Cheers
Mike

1 Like

I would entirely agree that its possible on SSB. AM is completely different and much harder to receive as Andy rightly quantifies.

I worked ZL twice and VK twice yesterday morning. ZL2AJ was impressively above the noise and the QRM.

Also don’t forget you need to de-rate your PA to withstand the constant duty cycle of AM.

Jonathan

I’ll be having a go… the 817 does AM and I have a some HF PAs which can be pushed into service. One will do 100W when driven with 10W so should be OK for the 5W the 817 produces. Shame it weighs a bit so it wont be going on a long walk!

Andy good luck.
The Flex 5KA AM mode default is 25w carrier unless you poke about in the PowerSDR software which I don’t do. So your setup on hill somewhere should work very well given a fair wind from Sol as always :wink:
Cheers
Mike