Storm Alex. QRM

I can report that all the rigging and daily inspections insured that the end-fed antenna stayed up well despite storm alex lashing down wind and rain of epic proportion !

Whilst I have been enjoy several QSO’s on other digital modes (SSTV, BSPK) other than FT8, id thought I do an update on the next steps for the End-Fed antenna.

Whilst my signals are not bad, there is a noise floor present. Whilst I have largely removed alot of sources of QRM from ‘the shack’ (see earlier posts on QRM) my end-fed antenna seems particuarly good at picking up ‘noise’. Maybe its good to state what I think noise is as well.

When I tune the radio, I should be able to, ideally, hear all stations on that frequency (and mode). What noise brings is either man-made or remote interference to a weak signal. For noise that is ‘local’ the weak signals hide in a ‘noise’ band, this can be upto S9 for thinks like washing machines/VDSL/construction equipment.

With the ‘local’ noise its possible to use the an external antenna (lets call that a receive antenna) and transmit on the existing antenna, then between the two ‘phase’ the noise until it is no longer present.

I am going to use the MFJ-1028 noise canceller as I was using this already with my Kenwood and DX-Commander multi-band vertical, but as both a send and receive antenna making using of the ‘T/R Delay’ – The Icom 7300 doesnt come with its own ‘receive only’ port unlike its ‘bigger brothers’ in the Icom range, but is easily adapater to have one via the a plug-in kit from Inrad.

The installation looks simple enough as shown in the video below. I face the challenge that I am also using an external ATU (MFJ-993B) so getting both ports in will mean doing the install slightly differenty.

INRAD RX7300 mod

I have a number of antennas i could use as a receive only, but a recommended ‘noise gather’ is the ‘mini-whip’. I picked mine up off ebay and it arrived in a bout a week.

I have yet to install the miniwhip, but have all the necessary parts, including a rather impressive 4th ground pole ! I will be following the guidance from the following video

I will first try using the mini-whipa and end-fed combo and feedback on results !

Hopefully there will be less bad weather in the coming week allowing more ‘build’ work outside, for now i’m glad my masts have stayed up and we are all staying safe at home !

Until next post – 73 !

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