Month: February 2016

Beginners Guide to 5 MHz

If you’re a UK based advanced (full) license holder then you already have access to 5 MHz without the need for any special NOV’s. Most modern radios will already transmit on 5 MHz, others will need modification or wideband for TX. If you have tested your radio on 5MHz and it wont transmit then you could take a look at mods.dk

So lets assume your radio is ready to go..

5 MHz is not like other amateur bands, we don’t have one continuous allocation, more segments of activity.Like the primary user its best to stick to USB on 5 MHz, although technically no reason why you couldn’t use LSB ! The band has pockets of activity, some frequencies are used for CW, Data and Phone. All of the frequencies I quote will be USB dial freq, and these could form the basis for you to program into memory channels. While the new allocation can be portrayed as “band segments”  it’s often easier to think of discreet channel numbers.

If you hear another amateur calling CQ be sure to check the band allocation as not all channels have been harmonised. This can even apply to returning a CQ call from another UK amateur, check before you transmit !

5mhz_taz_guide

You can download a PDF of this guide to keep by your radio here.

A PDF visualising the band plan is available to download on G3NRW site. The RSGB have also provided a guide online.

The RSGB provide a handy guide to ensure all of your signal remains in band.

USB-on-5MHz-Channel

Power is limited to 100w from your radio, and amateurs are secondary users (MOD is primary) I would suggest additional care is taken to ensure you always operate in band and identify your station call sign at regular intervals. Operating away from your main station address is permitted either /P or /A but no mobile usage is permitted.

The band is ideal for short range NVIS contacts during the day, typically 50 to 400 miles, and after dark the band does support some further DX. In the winter the band often closes shortly after dark, but in the summer it will support short hop NVIS all night.

The band does support various digital modes CW, JT65, JT9 and WSPR. The centre of activity for each mode.

CW – 5260 and 5262

WSPR 5287.2

Olivia 5366.5

FSQ 5367.5

73 Dave M0TAZ

How far does 1mW go ?

Do you remember playing as a kid with the short range 49 MHz walkie-talkies ?

49MHZ_1_Walkie_Talkies

49 MHz Walkie – Talkies

We used to play with these often as a kid, and the range was shorter than your voice ! With an output between 5 and 50 mW these could often struggle to communicate more than a few meters.

Still the fun we had trying to extend the range.

The Elad FDM-DUO has a 0 dBm o/p on the rear that will provide 1mW out from 100 khz to 156 MHz

 

The Elad uses a SMA female connector on its rear, and using a ebay special connector I routed this into my ATU and doublet antenna matched for 7 MHz. I wanted to run WSPR at 1mW and see what decodes I could achieve.

Over the course of the next couple of days I ran the Elad both at night and during the day. It was hard to achieve any decodes at night, but in the day I was decoded on many occasions from stations in the range of 50 to 770 KM.

Best DX was 2 spots by Denmark based station 5P1B at 770 KM.

The following statistics provided by WSPR.net database

 

 Stations who decoded M0TAZ v Signal @ 1mWsignal m0taz

Stations who decoded M0TAZ v Distance @ 1mW

decoded m0taz

 

You can download the free WSPR software provided by K1JT online. WSPR reports are uploaded and databased online.

73 Dave M0TAZ

14 MHz 2e Homebrew Quad

Homebrew 2e Quad for 14 MHz

The project was to build and test a 2e Quad antenna for 14 MHz, I wanted it to be lightweight and portable. The antenna had to be packed away in the car after a contest, so some parts of the antenna had to conform. The boom could be no longer than 3.5m, and the spreaders must be retracted for storage.

Cost should be under £100 for all the parts delivered.

The design uses fiberglass fishing poles, each pole is 4m fully extended. The project uses 8 poles. The poles will be fixed to the centre clamp using exhaust brackets, as they come complete with “U” support bracket. The size of the exhaust clamps will depend on the size of the roach poles.

The aerial will be 8m long, and 5m wide (see diagram) and the feed point will be at the bottom of the driven element. You may require some matching at the feedpoint, although mine was close to 50 Ohms.

You can find many online quad calculators, one that worked well for me is located here.

Here you will see the basic quad element, the basic construction is the same for both the driven and reflector. Here you will see the basic layout.

quad

 

 

Photograph of parts required. (Click to expand pictures)

SDC11719

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8012506452_6088d87683_z 8037251080_d378abc11a_z 8256934793_d3123faa8e_z

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Having fun with the Quad and linear amplifier. QRO HF portable

CQ WPX RTTY Operating Report

Managed to work a few in the CQ WPX RTTY contest this weekend using a basic setup at home. The rules for the contest  can be found online and the exchange is 599 and sequential number.

Station Kenwood TS990 @ 30 to 200w.

Antenna 1 – Doublet Antenna 10m per leg @ 10m

Antenna 2 – 9m vertical roach pole with CG5000 Auto ATU at the base.

Antenna 3- Avanti Sigma 5/8 wave ground mounted vertical for 28 MHz

In total I worked 114 stations, mostly on 21 and 28 Mhz. It was nice to see the higher bands open with a good selection of stations worked from NA – 55, SA – 7, EU -43, AF – 4, AS – 8. The operating was search and pounce and ad hoc during  the weekend. I did hear Mexico and India but I was unable to work them on my wire antenna.

The amplifier is a solid state HAL1200 that will run up to 400w RTTY and is rated at 1.2KW.

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The vertical antenna worked well using the auto ATU at the base, the CG5000 is rated at 800w PEP and 250w continuous, so being driven by the TS990 at 200w RTTY is no problem. I found the 9m roach pole would load quite well on 14 and 21 MHz, although the antenna length was not well suited for 28 MHz. The 5/8 wave vertical worked well on this band, and most stations I could hear was able to read me.

Here is a look at the 21 countries worked.

cq-wpx-2016-m0taz-countriesjpg

 

I did hear quite a few JA stations around 8am on 21 MHz.

Pleased to work V55V in Namibia and P40FA and P49X in Aruba.

In North America I was able to work   55 stations in 20 states.  West coast states included Arizona, and Nevada.

 

 

 

 

 

I used SH5 a contest log analyser  to create some KML files to view some of the QSO on a world map

cq-wpx-2016-m0taz-usacq-wpx-2016-m0taz-eu

 

73 Dave M0TAZ

 

0dBm 1mw input – Wideband Amplifier

Adventures of a broadband amplifier.

Some radios are equipped with  a 0dBm (1mW) output that can be used to drive an amplifier. The advantage of this output is it usually works over the entire transceiver range. So you can often obtain 1mw from 10 Khz to 60 MHz.

I recently read an article in Radcom from Dave Pick G3YXM and he had  purchased an amplifier from ebay. Dave confirmed it was this model with an operating frequency range from 1 to 500 MHz.

Like this one using the search term ” 1MHz – 500MHZ New HF FM VHF UHF RF Power Amplifier For Ham Radio + Heatsink”. If you wanted to use this below 1 MHz that’s possible but you will need to swap the inductors for larger values.

Tests without any changes showed 1mW in @ 1.9 Mhz = 1.6w out. The power out seems to drop to 100 mw below about 500 Khz. I also tested the amplifier at 144 Mhz and the o/p was around 1w.

Hopefully with a few changes this will allow me to run a small amount of power on 472 Khz WSPR.

1mw amp 1mw amp 2

 

© 2015 Dave, M0TAZ