Boltek External Antenna Details & Build Info

Home  System Config Antenna Parts

The Boltek Lighting Detector requires an antenna in order to pick up and process the received signals before being passed to the processor to do its bit. The antenna block appears waterproof with the exception of the RJ45 connector at the base of the unit.

I did lots of reading on the excellent weather forums in order to see how others have mounted their antenna and made them fit for external use (without buying the bespoke housing, which is quite expensive), my humble effort have been based on the path trod by others. The reason why I wanted it outside rather than in the attic space is that I had to have the squelch turned up to 10 on the LD-250 as the thing was going bananas, picking up all sorts of household electrical appliances being switched on and off, once mounted outside the squelch is at zero with only a few odd strikes noted and within two days of being fitted outside picked up a verified storm over Paris.

Part 1 - The build

The first task was to find a UK supplier of the plastic parts needed to make the antenna housing, metal parts have an adverse effect on reception, therefore the advice is to use non conductive parts only for the housing, this immediately discounted using an empty beans tin!, fortunately I found a company who were brilliant and had all the bits I needed substantially cheaper than buying a factory unit.

The company is Henderson Plastics in Dereham, Norfolk, and I can not recommend them highly enough, the parts list and a drawing of what I was trying to achieve can be found by clicking here.


 Parts delivered and checked
  Straight cut for once!
  Old trick of using A4 paper wrapped round a pipe to give a straight cut.
Dry Fit

                                   Antenna affixed to insert pipe, the connection is at the base of the antenna, and when installed will be pointing down.

Antenna Bubble Assembly, I did try to thread the plastic insert so the machine screws would tighten, this failed dismally, so I hot glued the nuts to the inside of the insert instead.

NOTE: The front face of the antenna has to point North, the plastic screws which hold the assembly sections together have been fitted orientated to point North when installed.

I did look at venting the antenna as it does get quite warm when on, the measurement shown was taken indoors (39oC), I decided not too vent the enclosure as I didn't want it to end up a warm and cozy wasps nest, only time will tell if I have made the right call.
Part 2 - Safety Top    

The Antenna was going to be mounted high on the gable end of the house, unfortunately we have a shed which the ladder had to bridge and this stopped the ladder being at the correct angle, the good news was that is was footed into a grass verge which would prevent it slipping out from the wall, to stop the ladder from sliding sideways (highly unlikely with rubber wheels fitted to the top of the ladder), I took no chances and fitted a self screwing eye bolts into the brick and used a car luggage ratchet strap to bind the top of the ladder to the wall.  The eye bolt uses an 8mm hole, so I could of either removed the eyebolt at the end of the job and fill the hole with some clear mastic which could easily be removed for next time I need it, or simply leave it in, this I decided to do as knowing me I would have misplaced the eye bolt, and it's not really noticeable, (if I had white painted rendered wall it might have been a different story)!.


Note that the bolt is near the edge of the brick, this is to avoid the hollow section of the brick (the frog).    

Part 3 - Mounting to Antenna Top

Once I'd made sure the ladder was secure and changed my pants :-), I used a hot dip galvanized 150mm aerial bracket, this was fixed to the masonry with 4 x 12mm expanding rawlbolts, (I figured if everything was to fail whilst I'm up the ladder, at least the bracket would hold me).

Once the bracket was fixed, I drilled a hole, outside to inside through the mortar at an inclined angle,  to stop any water entering the cavity, I did fit a drip loop with the cable anyway, but it's always good practice.

The Boltek comes with 50' of Cat 5 cable terminated with a RJ45 connector (purists will balk at the generic term RJ45, just suck it up), a 12mm hole is just big enough for the connector to be passed through from the attic to the outside with care, to make sure I didn't damage the connector, I wrapped some insulating tape around it, not so much as it bulks it up, but just enough to protect the pins and the plastic tab which latches in the antennas socket (if this tab gets snapped off it would mean crimping on a new plug as it would not 'latch' into the socket, way too much work when a bit of tape and care can stop this), so the connector and cable bridges the cavity with ease I taped a straightened out coat-hanger to the front of the connector, it was a piece of cake then to gently pull it through from outside.

Once plugged up, I smeared some silicone grease around interconnecting PVC parts that allow access to the antenna in a hope that it will be easier to take apart later should it be needed, the assembly then had the M5 plastic machine screws fitted and it was good to go.

I did not cut the cable which came with the kit as this allowed me to make up the antenna connection nearer to the ground which is always a good thing, with the slack being pushed back into the attic space and neatly coiled up in there.


                                                                      Antenna laid out ready to go skyward and a good shot showing how the ladder was securely footed in earth

Housing with cable passed through ready to connect to the antenna.

This is one of those moments where you don't step back to admire your work!

Cable with drip loop and hole sealed with mastic which sets clear.








Take me to the Boltek LD-250


Solar & UV Sensor Relocation - February 2014

To allow the sensors to have an uninterrupted view of the skyline, I decided to mount them onto the Boltek external antenna assembly, this was quite simple to do as most of the hard work had already been done. I ran a Cat5 cable to the ISS from the loft and extended the cables from the ISS sockets for Sun and UV to a breakout box, from here the sensor wires were extended and passed through the wall to the mounted sensors.

The sensors were mounted within a domes cap which had been drilled to allow for a snug fit of the sensor, this cap was then fixed to a 90 degree elbow via an intermediate reducing bush by a silicon based sealant. Sections of pipework which will not require disassembly for maintenance were glued with plastic cement.