Hi Paul,
I'm glad everything is working well!
Having things mounted directly at the centre of a dipole is a great way to not lose any milliwatts in your feed or tuning system! (Provided your dipole is trimmed right of course). I like it.
In the past when I've done this with a simple QRSS receiver I built (see ) the temperature stability wasn't great, though it remained perfectly usable.
One good idea if you plan to hang it outside in the open, would be to enclose the beacon circuit in polystyrene and then put the whole thing in the box. The ploystyrene ultimately won't stop the temperature drift but it will drastically slow it down so you won't notice it so much. One of my beacons ( ) ran in my attic for 6 months. I had a thermometer in the attic too, and recorded temperatures over that 6 month period all the way from below freezing to over 40C. The beacon was above the insulation layer. In the summer the attic was behaving like a greenhouse (definitely, the weather never really gives us 40C temperatures in the UK hihi). The beacon frequency used to drift up and down slowly every 24 hour cycle, and a longer drift over the months. The total excursion was within a 30Hz range. But most importantly, whenever you saw the thing on a grabber, it was always looking horizontal. The polystyrene did a great job of smoothing out any fast temperature fluctuations, i.e. slowing them down.
0.000073 de Hans G0UPL
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--- In QRPLabs@..., "Paul Daulton" <k5wms@...> wrote:
I finisshed assy of beacon kit today. works fine. I set mine for 10.140040 mhz and 5hz shift at qrss 6
I plan to mount mine at center of dipole with a 5volt regulator in the box. I will send up 12 rg59 cable tv coax with f connectors. I wonder how temp stability will be.
Good job Steve and Hans.
thanks
Paul Daulton k5wms
