Loggings > HF Beacons

Coastal Slider Back On 4109.5

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l0ngwire:
The Coastal Slider on 4109.5 is back, about S3 here in central California at 0650z.  Wonder what repairs were needed to get it back on the air again?

stendec:
Good find, LW!

The Coast Slider is coming in well on my home RX and 120' dipole at 0550Z this evening, S6 or so. Nice to hear it back. It went off the air the same day as DW, so maybe it was damaged in the same storm. Hopefully the owner will post something.

beaconpop:
About two weeks ago, a hike was made to the beacon to investigate what happened. As expected, it was an antenna problem - probably caused by high winds over the ridge in the storm also took DW out on the same day back in April.

The Slider's 70' antenna wire is supported by small two pine trees, and lacked a way to accommodate movement of those trees in the wind. The strain caused the antenna wire to part at a solder joint near the EFHW transformer, leaving only 1' of wire connected. The beacon was found to still be transmitting though. Fortunately,  the PA transistor was still OK (not surprising since the beacon only 1/3 watt).

The antenna was shortened a bit and the solder joint repaired with added strain relief. The height of the antenna was raised by an additional 10 feet. This had the happy side effect of bringing the SWR down to <1.5:1, whereas It was ~3:1 when first installed. A bungee cord placed on end to hopefully accommodate strain when the support trees move in the wind.

Teotwaki:
The bungee was a nice bit of McGyver'ing! Hopefully it withstands the UV for many months until it can be upgraded on a future trip.

Here at home on the KX3 I have a pretty fair signal with some slow fades rolling in and out.

Glad you made it our there before June and thanks for the full report!

beaconpop:

Yes, hopefully the bungee cord will last a few months.

Just in case, a length of dacron para cord was paralleled with the bungee cord, so that if (when?) the bungee fails, the antenna will just sag rather than fall down.  An upgrade to a pulley and counterweight arrangement that would allow for greater movement and a constant tension is probably the way to go.

And as you noted in your logs, the beacon's frequency shift has increased to nearly 400Hz from the original design value of 170Hz. Thanks for the report. There's an RC network which determines the amount (and rate) of the shift; perhaps the component values have changed a bit. It'll be interesting to see if the delta-F stabilizes or keeps increasing.
 

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