Tuesday, October 5, 2021

Transmitting near water, a good combination


  Inspired by this blogpost and other blogposts from John MW1CFN  I finally had a hour to spend at the coast. Trying to work DX with QRP powers which, following John's posts, can be boosted to QRO when you transmit near water. You will never believe the difference till you experience it.

But at first I had a problem which previously didn't occur when testing with the MLA. When installing the FT-817, plugged in the antenna and switching it on  I suffered from a S8 noise all over the 20m band. At first I thought the heavy industry, lots of windturbines and hundreds of solarpanels around the location finally caused HF radio pollution. 

At first I thought about driving to another location, which is not as good as this one but further away from the industry. Then it occured to me that the noise could be transmitted from my new upconverter...

Yep, that's the grey box, the red one is my Li-ion battery. The advantage of the upconverter is that it keeps an constant 13,8V on the transceiver and so it will produce 5W power instead of 2,5W when the voltage drops to 10V.

I decided to unplug the upconverter and use the internal radio battery. Noise was gone immidiatly. I hoped the upconverter would not have this high impact on receive, I didn't notice the extra noise with my MLA. But it is an old saying between HAMs: You can't work what you don't receive, no matter how much power you run! So, I had to try with about 2,5W...but with an excellent receive.


Did I succeed? Watch the video and you will know...

For reasons unknown some people seem to have difficulties watching the video embedded in this post. So here is the link to youtube: https://www.youtube.com/watch?v=1G-mc3V-NAo

9 comments:

  1. Wahoo! He he. That started my day off on a good note! Congratulations! It is quite amazing, isn't it? People literally refuse to believe it, as you say, until you show them the evidence. I really must do some of my own videos!

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    1. Yes John, I was lucky enough to work a chinese station as well. Unexpected but great fun.

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  2. On another note, can you not simply run the rig off the 12V DC outlet of the car? The current draw is low enough not to pose problems with wiring. One other source of RFI you have to look out for is those 12V-5V USB outlet sockets you can install in a car (or just have as an external attachment). They always produce fairly significant RFI on many bands.

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    1. Yes, I can run it from the 12V outlet. But still when transmitting the voltage drops to around 11V which is not enough to produce 5W. The FT817 does switch back to about 2-3W. Not that it really matters...73, Bas

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  3. WOW, a very nice day operating QRP and mobile.
    73,
    Mike
    VE9KK

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    1. Hello Mike, actually not a day but a hour of operating. But very surprising for shure. 73, Bas

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  4. Mooi die BD7 met zo'n setup. Dat *zoute* water werkt als een flinke versterker. De kust is hier helaas wat te ver weg maar heb goede herinneringen aan de keren dat ik er heb gestaan. 73, Lars

    Misschien nog een linkje toevoegen naar je video?

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    1. Ik begrijp dat het filmpje niet door iedereen gezien kan worden? Apart. Of misschien is het op een telefoon moeilijk te zien. Zal er een link onder zetten.

      Ja Lars, Lauwersoog is ook zo een mooie plek, maar dat is dan weer 40km rijden hier vandaan. Eemshaven is natuurlijk in de achtertuin. Ik wil ook nog eens in Noordpolderzijl kijken, daar kun je met de auto ook over de dijk en dan een heel stuk het haventje in. Met hoog water geeft dat prachtige mogelijkheden. Die BD7MHZ was echt een verassing, ik had hem al een paar keer gehoord maar zoals je in het filmpje vernam kwam hij net boven de ruis uit. Je moet dan niet denken dat het niet lukt (deed ik wel) maar gewoon proberen (deed ik ook) en je ziet het, het werkt. 73, Bas

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  5. Excellent!! I have enjoyed great radio days when working by the water. Using only 2.5W I had lengthy QSO's with two Americans when I was on the beach in Northumbria. These are happy days when you can enjoy the great outdoors AND great working conditions with no noise and the natural boost of power from the sea.

    73, Tom.
    www.M7MCQ.com

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Thanks for your comment. Bedankt voor je reactie. 73, Bas