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<feed xmlns="
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<title>Gopher.ICU - Radio</title>
<updated>2025-11-13T00:09:40+00:00</updated>
<id>
gopher://gopher.icu/0/phlog</id>
<author>
<name>IanJ</name>
</author>
<link href="
gopher://gopher.icu/0/phlog"/>
<entry>
<title>Ham-Radio</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/Ham-Radio.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/Ham-Radio.md</id>
<updated>2024-02-22T00:50:31+01:00</updated>
<content><![CDATA[# Ham Radio
I started a new adventure into ham radio. The idea came to me during
the COVID lock-down but although I purchased the study material, for
some reason I got distracted and didn't follow up on it until just
before Xmas last year. To get things moving I bought myself a small
hand-held, Retevis RT85, so that I could at least listen and keep my
interest. Once I had been reviewing the study material again and
thought I was ready to take the exam I started to look for a local
examination centre. Luckily there was a radio club fairly close that
was approved to sit the exam. I ended up joining the club and doing
the final few weeks of studying with their assistance before sitting
my exam.
I took the examination on the 9th of Feb and was informed by the
invigilator that I had passed the same evening. Monday this week I
received my certificate so that I could request my licence and
call-sign. This was all taken care of within a few minutes via an
online form.
## The myth of HT's
Having viewed a significant amount of videos online, I thought my HT
would have me easily connecting to local repeaters and having a great
old time talking with the locals. The reality sadly was much
different. We have 2 repeaters within the town and although I can
hear their transmissions, including a Hubnet connected repeater some
24 miles away, I can barely be heard on even the nearest. 5w and a
rubber duck antenna just won't cut it in an urban environment. I have
to admit I'm not helped by the terrain as I am basically in the
bottom of a valley, but I really thought things would be better than
they are. Obviously I was super keen to make contacts having put in
all the effort to gain my licence but I feel pretty disappointed
after 3 days of not being heard, or being barely heard. Saying that
I have managed a few contacts, one of which gave me instruction
over-the-air, how to build myself a dipole antenna.
## The dipole
The instruction I received was to take a piece of coaxial cable,
strip off 19" of the outer jacket and separate the shielding and
center core and pull them in opposite directions to form the two
elements of the dipole. Through some fortune I had aquired some RG58
coaxial from the radio club last Friday evening, so I already had a
significant component for the build. I needed to keep the elements
separated and have some way of mounting it. The first thing that came
to my mind was a long straight piece of plumbing tube that I had
pulled out of the loft when we first moved in. I measured a length
about an inch longer than the total length of the dipole and cut the
tube. I then drilled a hole in the center of the tube to be able to
feed through the RG58 cable. I made a small hook on the end of the
cable so that I could try to poke it through the hole and then
proceeded to draw through the cable[1]. Once I got close to the
elements I fed in the wire section in its plastic jacket, put a cable
tie around the coaxial just below where the two wires separated[2],
and proceeded to pull it down the tube. This eventually resulted in
the braided half of the dipole being pulled in and both elements
being centered in the tube[3]. I have ordered an SMA male to BNC
female connector for the radio and a BNC male to RG58 compression
plug for the end of the coaxial along with a Diamond SRH701 antenna.
The 19cm Diamond should be an improvement over the standard rubber
duck for portable use and I will use the dipole, vertically mounted
in the loft, when at home.
There are a lot more knowledgeable people at the club than me with
regard to antenna so, I will see if we can test the SWR of the dipole
and make any adjustments on Friday evening, before I connect it to
the radio. Hopefully the connectors will be here by then...
[1](
gopher://gopher.icu/I/phlog/Radio/images/dipole2.jpg)
[2](
gopher://gopher.icu/I/phlog/Radio/images/dipole3.jpg)
[3](
gopher://gopher.icu/I/phlog/Radio/images/dipole4.jpg)]]></content>
<author><name></name></author>
</entry>
<entry>
<title>What-a-difference-a-dipole-makes</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/What-a-difference-a-dipole-makes.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/What-a-difference-a-dipole-makes.md</id>
<updated>2024-02-24T01:10:54+01:00</updated>
<content><![CDATA[# What a difference a dipole makes
I simply cannot convey to you the importance of a good antenna
system. My first days as an amateur radio operator had been a huge
disappointment to me. My expectations of being able to connect to
local repeaters with ease and make contacts around the world using
Hubnet were shattered within the first 2 hours of getting my
call-sign.
From the ether in those frustrating hours a voice came and instructed
me how to build myself a basic dipole antenna[1]. I had to wait a
couple of days for some connectors to arrive but now that they have,
and the antenna is operable[2], things have changed significantly.
Today I made my first contact on simplex. I had set the frequency on
my HT to the 2m calling channel and had put a CQ call out but no
answer came. Then a strong voice came through calling CQ to which I
replied, half expecting not to be heard. To my surprise he asked me
to repeat my call-sign, which I proceeded to do in phonetics to make
it as clear as possible. Bob was his name, an 83 year old gentleman
that lives not far away. We had a great chat for about 30 minutes,
him explaining the gear he was using and how long he had been an
amateur and my doing likewise. He said there wasn't much traffic on
2m these days, which is what I have read pretty much everywhere, but
2m had seemed to work better for me. Maybe due to my terrain, or my
limited power, I'm not sure which but it has so far given me a better
experience. The local 2m repeater also seems to be more friendly to
my tinkering and connecting it to other systems, like Hubnet. I
managed to link the repeater into the Hubnet system and make a
contact with another recently licensed amateur who's journey I had
been following from the sidelines by listening into Hubnet and his
contacts there. It was great to finally be a part of the
conversation, rather than just listening to it.
Thanks Paula!
[1](
gopher://gopher.icu/0/phlog/Radio/Ham-Radio.md)
]]></content>
<author><name></name></author>
</entry>
<entry>
<title>VHF-and-UHF</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/VHF-and-UHF.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/VHF-and-UHF.md</id>
<updated>2024-03-02T19:29:04+01:00</updated>
<content><![CDATA[# VHF and UHF
It was never really my intention to invest too much time, or money,
into UHF or VHF. Due to my location, in the bottom of a valley, I
didn't think it would work very well and I would be heavily reliant
on repeater infrastructure. For me, being reliant on infrastructure
defies the object of the exercise which was station to station
communications, should there be some event that would interrupt our
more common communications channels.
After nearly two weeks of operating, my opinion has changed a little.
On simplex, station to station, I have spoken to a handful of locals
, a couple of contacts on higher ground further a field and also one
contact some 26 miles away who gave me a 5 & 9 report. I have
frequently used a Hubnet linked repeater some 20 miles away and made
a number of local contacts via the local repeaters. I have been
pleasantly surprised by my range in certain directions and confused
by it in others. There is a repeater practically on my door step some
4 miles away and I am unable to use it, but I can be heard clearly on
another some 20 miles away. RF is a strange beast indeed.
## Summary
I still don't intend to invest heavily in UHF or VHF but my attitude
towards it has certainly softened over the past week. I have some
better quality coaxial cable which I will install in the next week or
so. Higher frequencies suffer greater losses of signal on poor
quality cable. Without changing the antenna or any other component
this should improve my signal due to reduced losses in the cable.
Like with low powered computers, there is satisfaction to be gained
by operating low power and squeezing the most out of it. Bear in mind
that all the above was achieved with a Retevis RT85 5W hand held
radio that cost 23 GBP, a piece of RG58 coaxial cable and piece of
plastic waste pipe ...
## My station
* Retevis RT85
* Diamond SRH-701 19cm antenna (for portable use)
* Retevis RT85 extended battery pack
* SMA-M to BNC-F connector
* 10m of RG58 coaxial
* BNC-M to RG58 connector
* piece of plastic waste tube (outer of the dipole)
* Ring ferrite to choke the RF from the exit of the dipole.
## Future upgrades
* PSF 1/4m high grade UHF/VHF cable install
* Make a slim-jim antenna from 300ohm ladder line
* Hand microphone ?]]></content>
<author><name></name></author>
</entry>
<entry>
<title>Morse-Code</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/Morse-Code.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/Morse-Code.md</id>
<updated>2024-06-04T14:42:00+02:00</updated>
<content><![CDATA[# Morse Code
* The length of a dot is one unit.
* The length of a dash is three units.
* The space between parts of the same letter is one unit.
* The space between letters is three units.
* The space between words is seven units.
## Letters
A .- B -... C -.-. D -.. E . F ..-. G --. H ....
I .. J .--- K -.- L .-.. M -- N -. O --- P .--.
Q --.- R .-. S ... T - U ..- V ...- W .-- X -..-
Y -.-- Z --..
## Numbers
0 ----- 1 .---- 2 ..--- 3 ...-- 4 ....- 5 ..... 6 -.... 7 --...
8 ---.. 9 ----.
## Punctuation
.-.-.- , --..-- ? ..--.. ' .----. ! -.-.-- / -..-. ( -.--.
) -.--.- & .-.... : ---... ; -.-.-. = -...- + .-.-. - -....-
_ ..--.- " .-..-. $ ...-..- @ .--.-.
## Alphabet Trees
Follow the branch left for a Dit and right for a Daa.
### Starts with Dit
.
E
________________|________________
.. .-
I A
_______|_______ _______|_______
... ..- .-. .--
S U R W
___|___ ___|___ ___|___ ___|___
.... ...- ..-. .-.. .--. .---
H V F L P J
### Starts with Daa
-
T
________________|________________
-. --
N M
_______|_______ _______|_______
-.. -.- --. ---
D K G O
___|___ ___|___ ___|___
-... -..- -.-. -.-- --.. --.-
B X C Y Z Q ]]></content>
<author><name></name></author>
</entry>
<entry>
<title>VHF-Portable</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/VHF-Portable.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/VHF-Portable.md</id>
<updated>2025-02-08T21:20:14+01:00</updated>
<content><![CDATA[# VHF Portable
I've operated 2m portable on a number of occasions now. Twice already
this year and a handful of times last year with various pieces of
equipment.
If you have a good take-off, even with just 5w and a modest whip
antenna you will get out pretty well.
### Operating Portable
When operating portable you want to keep your radio kit as compact
and light as possible. Only deviate from this basic principle if you
have a specific goal in mind and the extra weight and complexity will
significantly improve your chances of success.
### My setup
Personally I have found a 5w dual band hand held radio to be more
than adequate for the job and perfect for SOTA type activities. My
own radio is a Retevis RT85 with an extended 2800mah battery.
Coupled to this I use a roll up slim-jim 2m antenna and about 6m of
mil-spec RG58 coaxial with BNC connectors, male one end and female
the other. The male end attaches to a BNC adapter that screws onto
the top of the radio, the female end to the BNC connector on the
antenna. The antenna is suspended from a 5m fishing pole to get some
extra height.
Gear list:
* Retevis RT85.
* Retevis RT85 2800mah battery pack.
* 2m roll up slim-jim antenna with male BNC connector.
* 6m mil-spec RG58 (male BNC one end, female BNC the other).
* BNC to SMA adatper for the top of the radio.
* 5m fishing pole
* Two stretchy velcro straps (to tether the fishing pole).
### Other considerations
You may well need something to sit on. Often I found somewhere that I
could operate and tie the pole, but not some place comfortable to
sit. The floor has often been muddy.
A flask and some snacks (tea and biscuits?) if you will be out for
some time.
Even if it doesn't appear cold out, when you are stood on top of a
ridge or peak and exposed to the wind chill, you can lose a lot of
heat quickly. Take some warm layers and gloves.
A small notebook for logging your contacts, waterproof ones are
available from camping and outdoors stores. You could use your phone
but that could run down your battery and then you can't make a call
if you should have an emergency.
### Summary
In short keep it simple, keep it light and you will have plenty of
fun hilltopping / doing SOTA activations.]]></content>
<author><name></name></author>
</entry>
<entry>
<title>HF-Portable</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/HF-Portable.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/HF-Portable.md</id>
<updated>2025-03-06T01:28:21+01:00</updated>
<content><![CDATA[# HF Portable
Today I finally set up my portable HF station[1], just in the garden
for a trial run.
I had recently bought a pac-12 portable vertical antenna in
anticipation of doing some portable HF operating this year and had
been itching to have the opportunity to set it up.
I did some experimentation across the bands using the SWR meter on
the rig with the antenna tuner disengaged. My results didn't exactly
tie up with those in the rather confusing chinglish manual and it
wasn't clear at first that for use on 10m band you don't need the
coil or 4 aluminium base rods.
On 10m the SWR is 1.0 right across the band, which was very
encouraging. I managed to get similar results on 20m and acceptable
results on 40m also.
Hopefully in the next two weeks I will have the opportunity to use it
on a field day. Although I really could do with ditching the lead
acid motorcycle battery in favour of a LiFePO4...
]]></content>
<author><name></name></author>
</entry>
<entry>
<title>HF-portable-pt2</title>
<link href="
gopher://gopher.icu/0/phlog/Radio/HF-portable-pt2.md"/>
<id>
gopher://gopher.icu/0/phlog/Radio/HF-portable-pt2.md</id>
<updated>2025-04-29T14:03:49+02:00</updated>
<content><![CDATA[# HF portable pt2
Having enjoyed operating portable with my HF radio setup and being a
little disappointed with the number of contacts last time. I decided
to try again over the Easter holiday.
## SOTA Saturday
Saturday, I went back to the same SOTA summit as before. This time
with a lighter load, due to the LiFePO4 battery and being more
critical over what I took along. Last time there were some items I
didn't use and it seemed a bit silly to carry them up to the summit
for a second time.
Unfortunately after operating on 40m for about 1.5hrs, the weather
took a turn for the worse. As it started to rain, initially I covered
the radio and battery with a waterproof coat, thinking it might just
be a passing shower.
I toughed it out for a while. However, on seeing more heavy clouds on
the horizon I decided to pack away and save my gear getting drenched.
By the time I got back down to the car park the rain had stopped. I'd
about had enough anyway and there were no guarantees about the
weather as the rain had not been forecast.
## Sunday high ground
After returning home Saturday afternoon I arranged to meet up with
another local amateur radio operator to go out to another local high
spot. He wanted to activate it as it is located in a valid POTA park.
His plan was to operate on 20m so, as I hadn't managed to attempt any
contacts on 10m the previous day, I decided to just operate on that
band. I was surprised initially when tuning around to find a net
going on with at least two audible VK (Australian) stations.
Unfortunately they were just saying their goodbyes, so regretfully I
didn't jump in to make the contact.
10m is an interesting band, when it's open you can get some more
exotic stations. I was happy to make a contact on the Greek island of
Crete and in Turkey, Istanbul as well as several Russian stations.
## Conclusion
As with most things, there are always improvements to be had. However
for only three attempts operating HF portable, I think it went fairly
well.
Further improvements can be made by reducing the size and weight of
what I'm carrying and the simplicity of the setup. Currently it takes
more time than I'd like to assemble and disassemble the station.]]></content>
<author><name></name></author>
</entry>
</feed>
