Equipment for PMR446 antenna upgrade ordered and a few other bits

I have placed an order for an SWR meter suitable for the PMR446 channels, I have also added tp this order some PL259s suitable for some cable I found I had lying about which is suitable for use on UHF but not as heavy as RG213, an SO239 coupler identical to what is fitted to the T2LT so the antenna and feeder can be connected together (I will be sealing this up with black sugru to protect it from the elements) and a SMA-F to BNC adaptor to fit the Wouxun in order to attach my Nagoya NA-771 to it when it becomes free again (once the Intek is on the bazooka and operating happily into it)

The SWR meter I have ordered covers from 140MHz (meaning I can use it on 2-meters to double check the slim-Jim on a radio and in situ once I have a license), all the way up to 525MHz (so PMR446 is included), my good CB SWR meter is valid up to 200MHz so for 2-meter antennas I can compare the readings.

The bazooka will be checked for SWR in two places, the first being at Whaston Road car park, my favourite DX spot close to home, the SWR will then be rechecked when the antenna is up in the air, I still need to add some rigidity to the driven element to keep it as vertical as possible (PMR446 units all have antennas that are near enough vertical as almost all type approved PMR446 radios are handheld units (the exceptions to this being the Intek DRS-5070 and it's cosmetically identical predecessor, the Midland BaseCamp446, and the Alan Base446, but these all can operate on batteries and are still portable rather than fixed like a base CB or home Amateur station, the BaseCamp446 has a mic holder on it's rear panel).

I expect to take delivery of the items I have ordered in the middle of next week, and I expect the PMR446 gateway to be moved off the Nagoya and onto the bazooka by the end of next week, range tests will then be carried out once the antenna is up, including to Northallerton, I look forward to seeing if at last I can make it there on PMR446, it's a big ask but it's worth trying.

73 de 26CT730

Couple of updates

First of all, the PMR446 gateway radio is no longer operating using it's supplied antenna, it has now had a BNC socket fitted, with the bazooka unavailable to be used for this radio at the moment I have had to make a temporary arrangement using my Nagoya NA-771 antenna, this antenna is doing the job, the radio is still operating at 500mW, and the gateway is still covering roughly the same area it always has been, the radio did have to be rotated to accommodate the Nagoya (the stock antenna entered the rig at a right-angle and I don't have a right-angle BNC adaptor), I aim to get the bazooka up in a couple of weeks, which should vastly improve coverage, I am also looking into running my T2LT over some weekends from home on the fibreglass pole once I have a means to mount it in the ground, but I shall have to see what happens.

The TTI TCB-565, the basic rig with s-meter that I reported on a few days ago has just become available on Thunderpole's web site, at just under £80, as my priority is an SWR meter for use on PMR446 the replacement TTI rig will be arriving after I have finalised the 446 bazooka, I'll have to order it perhaps in the new year.

My amateur radio foundation training is coming along nicely, I have to get used to the morse code properly, which means a couple of hours of it with a pair of headphones (my trusty Sony MDR-V150 headphones would work for this) listening to morse code, as I have to be up to a certain standard to pass that assessment, all the assessments need to be marked off before I can take the exam.

That is all there is that really needs to be updated, it's time for me to get on with other things, I've hit the limit on what I can and cannot do radio wise today, the bazooka antenna can't be tuned today, but it can when I get an SWR meter, I hope to place that order this weekend.

73 de 26CT730

Bazooka antenna assembled

As per the instructions of Jason 26CTX965 on his YouTube video, I have assembled a PMR446 bazooka antenna using RG58 coaxial cable.

The choke was a little bit of a difficulty to find a former for to begin with but I simply cut the handle off a cheap toilet plunger (no great loss as I can replace it).

The antenna needs to be adjusted for SWR, I face two problems here, one of which is that I do not have an SWR meter that I can use on PMR446, my decent SWR meter only covers up to 200MHz, so I need to get a new SWR meter, secondly is that I need to be able to connect the antenna to a radio and a feedline, the feedline is not a major issue as I have an RG213 feedline for my portable CB work anyway, a radio is as the feedline is terminated with a PL259, fitting the antenna socket kit on my Intek MT-5050 will not work without an adaptor as this is an SMA type connector, the modded Binatone Action 950 as you know has a BNC socket so again needs an adaptor, and my Wouxun, though not strictly legal on PMR446 also has an SMA socket so again requires an adaptor, though I need an adaptor for the Wouxun to use the j-pole I made at the club the other night.

The ultimate idea of using this bazooka antenna is to improve range of the PMR446 gateway, the gateway radio is currently using the antenna fitted to it and is attached to the window with suction hooks to give it some height in the Catterick and Northallerton direction (it has NEVER reached Northallerton and been usable there, but as the A1 is in range, only just, then a better antenna is called for as the A1 is a major through route in the area and good coverage there would be a bonus, as the Intek DRS-5070 is not fitted with an antenna socket out of the box then this needs to be done, the BNC sockets are generally cheap to obtain (the same time I used for my SDR enclosure should suffice with the outer connected to a ground in the radio (negative side of battery box)

I'll update this when the antenna has gone on the pole and been checked out for SWR.


73 de 26CT730

Amateur radio club night - 13th November

Yesterday evening was the evening of the local club meet, and we broke out the soldering irons and had a go at making j-pole antennas out of twin-feed cable for the 2m band, with varying degrees of success, the difficult part is stripping the twin-feed,

Fortunately we did not need to put them on a radio and ask one of the licensed members to test them, instead Chris G4FZN, the repeater keeper for GB3IR, brought with him an antenna analyser allowing us to test to see if our completed antennas were working fine without the need to connect them to a transmitter, mine was pretty good for a first attempt (bearing in mind all my previous antenna projects have been for 11-meters or the Delboy online RX-only 446 dipole and the last working one on transmit was my T2LT for CB, bear in mind I am also putting together a 446 bazooka antenna to the design of 26CTX965 and have not finished it yet).

This now means I have an antenna for the 2-meter band I can actually use once I am licensed, I see no harm in using it for RX-only applications in the mean time but I'd really like to test it out on transmit, the good thing is that my decent SWR meter works between 3 and 200MHz so covers pretty much everything I would be using apart from PMR446, which I will deal with later on, I shouldn't need to adjust the SWR but I will check it out either way.

Also there was mention of when I do my exam for my foundation, nothing is set in stone, a date will be decided later, in the mean time I have to do more training on Tuesday night.

Next club meeting is the 27th, though I am supposed to be doing forklift training that week I should still be able to make it to the club that evening.


73 de 26CT730

Small TTI CB radio with included S-Meter coming soon?

It came to my attention from Simon The Wizard's blog that there is a new TTI CB radio coming soon, the TCB-565, I already own a TCB-550 which I use for my CB gateway on the Free Radio Network, and though it's a good and basic radio which is suited to it's role I have found it lacks one useful feature that every other CB radio I own has, an S-meter.

TTI themselves obviously saw this shortcoming too with the TCB-550, TCB-560 and TCB-660 as none of these had an s-meter and introduced the TCB-565.

Normally I don't report on new radios, but this one is noteworthy having an s-meter, and this got me thinking, I could replace the gateway radio with one of these easily enough, provided that like the TCB-550 the internal speaker was plugged into the main board as the bottom cover should fit and it should fit into the TCB-550's rig bracket, also if the mic socket uses the same Uniden wiring as the 550 the interface would just simply swap over, should this happen then the TCB-550 will be re-purposed as just another rig.

From what pictures I have seen the radio does look good and the s-meter is in a prominent place above the channel display, I shall keep my eye on the usual UK CB suppliers and pick one up as soon as it becomes available and go from there.

73 de 26CT730

SDR enclosure almost ready for stage two

Posting this on my phone as the home QTH has no Internet connectivity since Friday morning, which has resulted in no PMR446 gateway in Richmond, unfortunately this is BT's issue as opposed to mine.

I found a second nut and machine screw today while tidying up, needless to say this allowed me to drill a second hole and fasten the USB port to the tin lid properly, I removed the SDR to drill the hole as I did not want to damage it, it was returned to the tin when the second screw was tightened.

The SDR is currently tuned to GB3IR, the local 2m repeater, the antenna is a 2/70 antenna so fine for this use, performance appears to be good, the next stage will be sealant around any holes to prevent leaks, then some vegetable oil for coolant as far as I dare fill the can, as per the information on SDR for Mariners, and a final bead of silicone sealant on the outside of the lid to be absolutely sure.

This has been a slow project but it is almost there, a scanner antenna will be next for this, hopefully I can see what this cheap SDR, when surrounded by metal and immersed in oil, can really do.

73 de 26CT730

PS, I hope to have Internet restored and the gateway operational soon

RTL-SDR enclosure prepped

I picked up 2 different diameter hole saws today to enable me to cut the hole needed in the lid of the tin for the USB connector for the SDR, the connector was fitted after a suitable hole cut and another hole drilled through for a screw (a second screw will be sourced and used later to finish the job).

A connecting lead for the antenna socket on the stick was sourced from the magnetic mount stick antenna that was supplied with the RTL-SDR stick, it was simply a small amount cut from the lead with the MCX connector intact, the cut off end was simply prepped and soldered to the appropriate points on the BNC connector, with the excess trimmed off, continuity was checked before the lead was connected to the stick.

The stick was then tested with just the antenna socket, I installed the SDR# software to do this, it worked as it should have done, the stick was then connected to the USB socket inside the tin lid and the tin closed up, it still works, the NA-771 antenna is not tuned for everything the RTL-SDR is capable of tuning to, but it seemed to work OK in the broadcast band, it of course worked fine in the 2-meter band and on PMR446 (PMR446 frequencies fall into the 70cm band in the US so to be expected). I tried it on 11-meters including on 27.555 MHz, but no luck, partly due to being indoors and partly due to being the wrong antenna for the band, a final test was to see if broadcast reception was eliminated while inside the tin, it was.

The last stage of this project is to fasten the USB connector down properly with one final screw, silicone seal the inside of the tin to be sure that no leaks can occur, fill it with oil after the silicone sealant has cured, and immerse the operating RTL-SDR into it, the reason I want it operating while I do this is to ensure that the stick continues to work while immersed in oil, SDR for mariners claims that it does.

It has taken me a bit of time but I finally have got the tin fitted out.


73 de 26CT730