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Technical Topics => The RF Workbench => Topic started by: Zazzle on July 17, 2018, 1523 UTC

Title: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: Zazzle on July 17, 2018, 1523 UTC

Heyho,

First: yeah... I'm still alive. I just agreed to some RL commitments (more than I could handle due to complications) and that basically killed all my free time in the first half of 2018. Not to myself: be more egoistical...

Seconds:Common and Precious 3 got father and gave birth to... okay... I stop being ridiculous.

The urge to build this beacon came kinda out of nowhere. I always felt for building a entirely solar operated beacon. The urge suddenly hit me hard. Those who follow my projects from the first day might remember that it was an idea that came up every now and then on the way). Anyway. The recent years gave me an good idea about the level of vandalim to expect. Another point is that I now have a source for cheap second hand and/or partly damaged PV module. So a loss doesn't hurt that much.

The frequency close to 'Common and Precious 3' was choosen on purpose. Even with the difference in RF power level (25W VS 2W) it allows a good comparison of the two setups.

It might also happen that I'll loose the location for my beacons during the next months. The city hall published ideas and plans about tearing the areal down, building homes on it.

A documentation with more details/pictures can be found on the Wiki here (https://www.hfunderground.com/wiki/index.php/Common_and_Precious_4). (Proof reading/editing anyone? :) )

Open issues...
Opsie #1, I forgot to tune the frequency back to 6.399,500kHz. It's running at 6.399.000 right now. Lucky me that I've build the TX unit with connectors so it's easy to take it home again.

Opsie #2: I've started redoing my Morse-2-Text routines and it took longer than expected. But I wanted to install the beacon on the scheduled weekend. So it's currently sending only 1Hz dashes.

Also... I might change the PV-Module. Chances are I can get my hands on a 170W type for a crate of beer. This provides more resources for operation during winter.

Overall: I'm very happy with this project. It's a good mix of proper engineering and not overdoing it. It also looks beautiful on the roof. Might sounds silly but those who know the beauty of such project might understand. :)

Circuits are about to follow as well.

(Side node: Eww! Whe wiki does a hard re-compression of attachments (pictures), eh? My poor beautiful and crisp pictures.)

(https://www.hfunderground.com/wiki/images/3/33/CaP_4_Setup-02.jpg)

Greetings,
Zazzle

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: ulx2 on July 18, 2018, 2001 UTC

SINPO is up to 32433-33433 with pocket receiver and 10 m random wire antenna. Received in Kyiv at 19.55 UTC 18 Jul 2018. Side QRM from C&P2. Dashes non-stop. Good signal for only 2 W.

Non-filtered recording: C&P-2 + C&P-4 (http://ulx2.byethost24.com/wp-content/uploads/2018/07/CommonPrecious10.mp3)
Filtered by audio post-processing (http://ulx2.byethost24.com/wp-content/uploads/2018/07/CommonPrecious10f.mp3)

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: Josh on July 19, 2018, 1904 UTC

(Proof reading/editing anyone? :) )

I'm on it!

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: SV1XV on July 22, 2018, 0622 UTC

Nice signal from COMMON AND PRECIOUS last night in Athens, Greece. Read more: COMMON AND PRECIOUS on 6398.5 kHz (http://sv1xv.blogspot.com/2018/07/common-and-precious-on-63985-khz.html) on my blog.

73 Costas SV1XV

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: Zazzle on July 24, 2018, 2336 UTC

Hey!

Reception might be weak. There's some RF getting out but not much. I guess the Transistor in the PA stage got fried. I did something realllly stupid. The box holding the electronics is mouted on the side of the PV panel. The panel faces south. Soooooo.. the sun past noon starts to shine on the box. There's a big black battery inside and the acrylic cover might have it function as a green house... heating the whole box up... which killed the transistor (which reaches approx 55°C with 20°C ambient temperature in the box.

Oh well... I'm gonna have to fix that later. So far the box got covered with a white sheet to reflect the sun and keep the battery from being cooked....

All those thing you need to pay attention to.

Btw: since all other Projects went off-air on Monday... I was pretty worried to find it already vandalised... but all is fine. Phew!

~Zazzle

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: ChrisSmolinski on July 25, 2018, 0007 UTC

I tried for your beacon this evening at 0007z. I can hear some beeping, but no obvious CW, so I may just be hearing something else, or some QRM

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: Josh on July 25, 2018, 1756 UTC

Sounds like a relocation of said transmitters to rural, out of the way spots, might help with keeping them on the air. If someone is intent on clipping coax, make them work at it.

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: edd on July 31, 2018, 2034 UTC

Reception near Moscow - https://youtu.be/mpLGkI8I-v4 Degen 1103, built-in whip.

Title: Re: Common and Precious 4 (on air, 6.399.5kHz, 2W)
Post by: muromdx on August 11, 2018, 0715 UTC

Reception (https://www.youtube.com/watch?v=PA48JDqxEZQ) in Murom, Central Russia. Rx: Degen DE1103, built-in telescopic antenna