Tuesday 3 May 2022

Helium Mappers

Using a Lilygo TTGO T-Beam to run Helium Mappers software. 100mW on the 868MHz band.

The code is by Max-Plastix

What is Helium ? Seen a load of small vertical antennas going up on nearby houses? Wondering why the price of good coax cable just rocketed? All the important things you need to know are:

  1. Paradigm Shift
  2. Decentralised
  3. Blockchain

OLED display comes with the unit but needs soldering on (4 pins)

A professional car installation, perfectly balanced on my phone holder

There's a holder for a 18650 cell but it runs on a USB power bank and no cell

Mapping the A590. This area was previously uncharted territory. Some transmissions are getting across Morecambe Bay from inside the car (see top right, receiving hotspot is at Heysham)

Some good locations in Barrow, getting across The Bay


Tuesday 14 September 2021

50p Door Intercom

50p from B&Q in the bargain bin. How could I say no?

The blob on a board is to generate an alarm sound.

Saturday 11 July 2020

Equipment List

Just a quick update on what I'm using..

  • Yaesu FT-7900 2m/70cm mobile. At home, connected to a 2m dipole in the loft (was in the car, but brought indoors recently).
  • CRT Millenium CB/10m mobile. In the car, with a springer mobile antenna on a Sirio magmount.
  • Yaesu FT-4X(E) 2m/70cm handheld. This is my main handheld radio for analogue FM.
  • Retevis RT8 VHF DMR handheld. Very similar to the TYT MD380 (same firmware and programming software). 
  • Wouxun KG-699E 68-88MHz handheld, covering the 4m amateur band. 
  • SDRPlay RSP1A software defined radio (receiver). Used for all bands, but at the moment it's my only receiver for SSB and data modes, so is often being used for receiving FT-8. 
  • The HF antenna is a dipole in roughly an L shape (no particular length), with one side along the gutter and the other sloping down to the garden fence.

Wednesday 26 February 2020

Retevis RT-8

Got the VHF version of the Retevis RT-8 DMR handheld for Christmas. There it is alongside my Uniden UBC3500 on a trip to Newcastle last month. 


Tuesday 17 December 2019

Last 20 QSOs

My last 20 radio contacts
95% FT8

Friday 6 December 2019

10 Years On

Ten years ago to this day, I sat in the Ashton Under Lyne Travelodge and started this blog which is mostly about my amateur radio activities (well I'd made one post in 2007 with this account but forgotten about it).
Since then, I've discovered quite a few things:
Other digital modes such as JT65/FT8
SDRs - both receive and HF transceiver
Digital voice - I've tried D-Star and DMR (then there's Fusion and even Network Radio, which I've not tried)
The 23cm band - and it was from the Travelodge I ordered a handheld with 23cm.

I'm much less active from portable locations now (it's over 2 years since I did a qualifying SOTA activation), which has also meant I've not had as much to write about.
At the moment I'm mainly doing HF FT-8 and WSPR using 5-10 watts into a dipole that's partly hidden under the gutter, have a Yaesu FT-7900 dual band mobile fitted in the car and a few handheld radios which nearly always come out on walks (even if receive only and not in the hills).

Something has broken in the Comet GP-15 tri-bander on my chimney (probably the coax plug), so here is the temporary loft dipole for 144MHz, connected up when I recently got all the decorations down.

Friday 5 April 2019

Yaesu FT-4XE

A couple of weeks ago I ordered myself a new dual band handheld, a Yaesu FT-4XE.
For the last 2 years, my main handheld transceiver had been a Baofeng GT-3, which cost only £30 but had some big problems, like being unable to use it anywhere there were other strong signals. On an external antenna at home it was unusable at VHF but even some locations out of doors strong broadcast signals were overloading it.
When Yaesu's new range of cheaper FM only handhelds came out, (FT-65, FT-25, FT-4), I suspected that they could be nothing more than rebadged Baofeng type radios, especially with them having features like FM broadcast reception (but no other wideband coverage of airband etc.). But after reading this review and it being the cheapest 'proper amateur' dual band radio by a long way, I decided to go for it.

It's a small radio, and you could almost call it credit card sized, here it is hiding behind a card.

 and next to the old GT-3
 Only a volume control on top, a tuning dial is one of the things you give up to save money. Using only buttons to move up and down frequency or through the memories is a pain unless you're going to be using the thing on a small number of channels. That and the slow scanning speed (6.5 channels per second, a whole 30% faster than the Baofeng's 5) are probably the things that make it still feel cheap. Some features may be limited by the transceiver on a chip RDA1846 which it shares with the Baofengs though. At least there are 200 memory channels for the radio to take a leisurely stroll through, compared with the Baofeng's 128.

Yes, it does 6.25KHz channels, at least for the 'E' model (the other model may not, there is nothing in the PDF version of the manual about it, with 5 and 10KHz being the minimum in there).

The real test of this radio's performance was connecting it to an outdoor antenna. I knew that the Baofeng could receive nothing on VHF when connected to my 6/2/70 tribander. The FT-4 received just fine, and gave realistic looking s-meter readings. There must be filtering to reject broadcast signals above (DAB) and below the receiver's 136-174MHz range, which is missing from the Baofeng.
S-meter S9 is around -96dBm and S5 is about 10dB lower, giving appoximately 2.5dB per point. There is a 'S10' and 'S11' above this.
The supplied antenna is about 16cm long, similar to other handhelds. For its size, it performed best near to the 144MHz amateur band compared to a few others of the same size I had around. On UHF though, it was actually worse than any other handheld antenna, which is surprising as I've found when testing handheld antennas at 430MHz there isn't very much difference between them, nowhere near as much as there is at VHF, and the higher frequency means a wider bandwidth.
Around 165MHz the antenna was worse than a no-name model of the same length which I paid less than £2 for on AliExpress, but that's going to be the price to pay for more efficiency on frequency, nowhere near as bad as the Alinco DJ-G7's stock antenna though.

Yaesu have made quite a good effort with the memory and tuning features of this radio, with 10 memory banks and 10 programmable band edges. Then there are Yaesu specific features like Automatic Range Transponder System, so obviously not just some other brand being re-badged.
The programming software is free from Yaesu, quite basic, no facility to import/export or sort frequencies, but allows you to organise the memory banks.
I found a video on YouTube showing the wiring of the programming cable (2-wire TTL, using R&S of a 3 pole 2.5mm jack plug) and made up a cable from an old FT-817 USB adaptor and a diode.

So, I wasn't disappointed with this radio, it was clear what it's limits were going to be before buying it (no tuning dial, no extremely wide receive coverage, no digital modes) but it does improve on the £20-£40 range of handhelds which are so common these days.
Unless you were going to use a handheld radio under very limited conditions (a local repeater which could be worked on a short antenna or indoors, monitoring a few channels rather than tying up a more expensive radio etc.), I'd definitely go for this rather than trying to save a few quid.

What about the FT-65? It's about another £25, bigger battery but is the performance going to be the same?