HTM-10 - extendable mast

Placement of a HTM-10 aluminium telescopic (click) mast. Approximate 10m high.
Up to three RG-58 coax cables can be fed through the mast tube.


HTM-10 with Diamond D-130
HTM-10 with Diamond D-130

A good begin for antenna experiments...

First create some extra antenna attachment points. Using four U-brackets will reduce stress on the main tube.

HTM-10 with T-bar
T-bar mount
T-bar mount
RG-58 in tube
RG-58 cable entry
HTM-10 inner details
HTM-10 inner details (notice limited space for cables)
Diamond D30 and D-130
Diamond X30 and D-130
Backyard view
Backyard view
Mast with EndFed detail
X-30 and EndFed UnUn transformer
HTM-10 Variable guying control
HTM-10 Variable guying control


The telescopic mast can be guyed on any height due to the use of pulleys (see below) and rope drums (right).

Started guying with 4mm (red/black) Hamrope.
Replaced the Hamrope with 6mm Mastrant rope (blue/black) for more strength and better stability.

HTM-10 Guing pulleys
HTM-10 Guing pulleys


One extra (smaller) pulley is mounted to have the ability to hoist a wire antenna to just below the guying point.

Guy rope tension

Guy compresion springHamRope and  Mastrant guying ropes have high strength, negligible elongation, low wet-ability, excellent UV radiation resistance.

But they still stretch out a little when becoming wet.
And most of the time when it's windy and need good rope tension, ... it rains.

A fence compression spring in used in one of the guying lines to determine wire tension.
The flexibility of the mast distributes the tension more or less equally across the three guying ropes.

Compresion springs

A spring has a linear distance to force ratio.

Experimented with several springs to get the right tension and reach.

September 2017 setup

Moved the D-130 Discone to fixed lower pole. Reducing weight and wind load for main mast.
This also makes room for a third HF antenna.

Setup change 2017-09-20
work in progress...
Antenna setup per 2017-09-20
X-30 (top), Fan dipole, End-Fed (box on T-bar), D-130 (lower mast)
Down position
Retracted position
Two level guying
Two level guying (6mm for top, 4mm middle)

Glass fiber stackable poles

Glasfiber stackable poles
Each pole 1.2m - 35mm diameter

To support the wire antennas.

Made from GFK/GRP glass fiber reinforced plastic
Total length : 1.30m, effective length: 1.20m
diameter: 35mm, wall thickness: 25mm
Color: green
Weight: 1Kg per pole
4x 1,2m pole
Two poles. Each 4 x 1,2m segment
Mast top view
Mast top  and middle guying view
Antenna installation PA0ROB
Antenna installation PA0ROB

Adding End-Fed for WARC

A second impedance transformer, housed in ABS 82 x 80 x 55 mm (ip65) box, for the WARC End-Fed antenna is added.

The lid of the box is mounted to the mast. This makes switching a transformer easy.

Second End-Fed mount
Preparation for second End-Fed transformer

EANTENNA EA270ZB13 5+8 EL. 144 MHZ./432 MHZ

EANTENNA EA270ZB13 5+8 EL. 144 MHZ./432 MHZ
EANTENNA EA270ZB13 5+8 EL. 144 MHZ./432 MHZ



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