RTL-SDR dedicated machine sort of set up

I have an old laptop with a display that has no working backlight, a Samsung RV510, and am putting this machine to use as a dedicated RTL-SDR receiver, it originally served as the now closed Richmond CB FRN gateway, with me having high SWR (and having to use a matcher), it remained closed for quite some time however the machine was in fact hibernating from the very point it was closed down.

It seems to run the SDR# software fine and works with both RTL-SDR sticks (I already know that the cheapo black one works, the NESDR SMArt was tested). so first test was with Soundmodem and APRS, it worked ok, though I don’t think I configured it correctly to pass packets from soundmodem to APRSIS32 so nothing was gated in that experiment.

Next was to decode DMR, it did not do well here either due to there being some noise on the frequency I could not seem to get rid of, though this was in the 70cm band and the supplied magmount is fitted with RG58, trying a piece of 213 and a dipole didn’t make a difference and destroyed my SMA-M to SO239 adaptor almost to the cost of the stick’s SMA-F connector (though the sheared pin was removed with Blu-Tack.

I am going to rehash my Handheld CB and PMR446 videos after either the Ripon or Blackpool rally, the first videos were all HT to HT (or in the 446 video between two units with fixed helical antennas) using this setup, the final location of this receiver of many talents will be next to my “Stranger Things” radio (the Realistic Pro-53 Patrolman, I call it that because it really looks like it was pulled from the Netflix series Stranger Things though I owned it before I heard of that).

The two videos will be done under the same conditions at the TX end, using the same radios (Intek MT-5050 for PMR446 and Midland Alan 42 Multi for 11-meters, both again using the stock rubber duck antennas), the RTL-SDR will be connected to an antenna using a lenght of RG213 to keep loss as low as possible, the antenna will most likely be in the window, outside if possible, and I want to make it from a couple of cheap CB antennas with the 3/8th thread on them as I have a dipole centre configured this way, that arrangement won’t be used for TX as there would be no choke.

The receiver works from as low as 24MHz right up to 1.7GHz. so 10-meters, 6-meters, 4 meters. 2-meters, 70cm and a lot of commercial, licence-free and aviation frequencies are also covered as well as the Amateur bands and CB frequencies, first things first is that I require a new SMA-M to SO239 adaptor and preferably a way to stop the SMA pin shearing off.

On closing I now have an extended battery to record video footage from the camcorder, this is so I can record footage of the Ripon and Blackpool rallies , Ripon is on Sunday (with an aim to have the video uploaded by Monday afternoon), Blackpool is two weeks later (with an aim to have the video uploaded by the following Monday afternoon)

73 de 2E0EIJ/26CT730

Leixen VV-898 compact mobile VHF/UHF radio

I became aware of a gem of a radio on the Charlie Tango forums, the Leixen VV-898, this radio is extremely compact so will fit in the smallest of spaces in the smallest of cars, and it is perfect for the foundation license holder in that it is maximum power of 10 watts.

Originally I was going to use my Wouxun in the car, however after seeing this rig it meant I could have something a little more permanent, the theory is that I should be able to use this radio to get into GB3IR from a little further away, this is in part due to my Wouxun only putting out 5 watts on VHF and 4 watts on UHF, my recently acquired Baofeng is similar in this regard.

Wiring this new rig into the car should not be that difficult, it wasn't for the CB though the power cables were too short, so I don't see any major issue with this rig, I will more than likely need some new reels of wire from Halfords though.

This rig retails at less than £100, Moonraker sell it for £99 give or take, Martin Lynch & Sons sell it for £90 with a programming cable or £80 without, though to be honest the story is always the same with all these Chinese radios, buy a programming cable.

This radio, like all the Chinese made VHF/UHF radios, can transmit on the PMR446 frequencies with the correct steps, but you do this at your own risk, I take no responsibility for illegal use of radio equipment.

With two weeks left to go before my foundation exam (yes, it's two weeks today) I have decided that once I pass (which I have every confidence that I will) I will get this rig ordered the same day, installed by the following weekend, with the antenna SWR check done at Whashton Road car park as per my usual routine for setting up mobile rigs, unless the proximity to GB3IR causes problems, which it should not do, or I have not received the needed information from RSGB before that date to get my license from Ofcom, I have, however, found out that these radios, or at least more recent ones, are equipped with a BNC connector as opposed to an SO239, this means an adaptor will be needed, but I can deal with that when I need to.

I will post a quick video to YouTube as well

Another rig to show up for me soon will be the Anytone AT6666 as I plan to order one of these when I get paid next week, probably with another YouTube video as well.


73 de 26CT730

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

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

Pre-DXpedition evaluation of Tan Hill

I took a ride up to Tan Hill today to evaluate how good a DX spot it really is, for PMR446 use I’d still advise on an external antenna mounted as high as possible, for CB a proper antenna would be beneficial, though I had stations incoming on a handheld, in this case the Midland Alan 42 Multi, notably some foreign stations on channel 8 midblock using AM. I did have a brief flick around on FM and also on 27/81 but AM appears to show more promise, SSB may also be very promising when I can finally give it a go, which may well be at Tan Hill.

I took some video footage on my phone and while I type this I am awaiting it to process before I upload it to YouTube, a later post will be that very video, which includes my very first call on AM, although because I was using a handheld I doubt anyone was able to hear me but with radio you just never know.

All I am left to do is sort out a shelter, build a T2LT and some suitable battery packs, acquire a pole to mount my antenna to, and hopefully I can get back to Tan Hill and keep DXing, I’d like to be up there in August on a Sunday.

So, a video is to come later one when it is finally uploaded to YouTube, and on Monday the President Grant 2 should be here on my desk.

 

73 de 26CT730

private listening issues and progress with the scooter CB

Now, as anyone in the radio communications hobby will know, pretty much every transceiver and scanner is set up as such to have a mono audio output, meaning plugging in a pair of headphones results in a dead left or right earphone, and for me this always causes a level of discomfort.

Today I purchased a pair of Sony MDR-V150 headphones, I have another pair of Sony headphones and have found them to work wonders, if you want good headphones, buy Sony headphones, of course plugging them into my radio resulted in there being one-side not working, not ideal if you want to use them with your radio, so here is what I did.

I used a piece of cable with a TS plug of the sort normally used to connect external speakers into rigs, the bare ends of the wire were soldered into a scrap of veroboard on which I fitted two resistors, originally at 10k Ohm but I reduced this to 1k Ohm as the 10k resistors made it such that I had to turn the volume on the rig and handhelds full up to hear anything when I tested it, I may use lower resistors but the 1k resistors are fine for the moment, the other side is a suitable socket for connecting any pair of headphones, even the earbud type, for this purpose it doesn't matter if the left and right are wired to either resistor the audio is mono from the rig and simply being split to both channels on the headphones, it's a fairly simple solution and cost me nothing as I had all the parts in stock already for at least one such adaptor, possibly two.

The scooter CB issue was approached today since the weather had dried up, QRM only appeared to be present when the starter motor was turning over, with the scooter's engine running QRM was not present, nor was it conducted through the cigarette lighter socket that I had fitted, and load on the scooter's generator was not an issue, even during transmit, this last issue was brought up with me some time ago when an idiot decided to tell me that I didn't know what I was doing and there was no way the generator would handle the load, as the Midland Alan 42 Multi is only a handheld it is designed to be quite energy efficient yet still work as well as a normal mobile rig, and the generator never once complained, even with the scooter's lights on, so an antenna and a motorcycle helmet headset are next on my list for that as of today.

So I am almost on air at home and mobile, and hopefully this week I can begin the journey to licensed amateur.

73 de 26CT730

Binatone Action 950 modifications

Note, For information only, I do not recommend or encourage modifying PMR446 radios, you do so at your own risk

One of my own Binatone Action 950s has been put forward as the radio, the other one of the pair will remain unmodified

This is the radio in question, this radio will be modified to include a BNC socket and antenna, a power mod does exist but requires some SMD components as well as a switch or two solder pads bridging, the bridge has been made but the components are not present so the radio is still at 500mW

This is the same radio as above but with the antenna removed ready for a BNC socket to be fitted

This is the radio with it’s BNC socket installed, the bottom part of the antenna has been used to accommodate the BNC socket, the BNC socket cannot be soldered directly to the board, a small piece of wire had to be soldered between the centre pin of the BNC socket and the antenna connection on the board, the ground is soldered to a nearby solder pad that connects to ground, for stability the area around the socket will be filled with some epoxy, this should stop it moving about as although the BNC socket is a tight fit, it does move a little so this is recommended

This is the antenna I intend to fit to the radio, Nagoya NA-771, this antenna is a dual band antenna for the 2 metre and 70cm Amateur radio bands, and as the latter includes the allocation for PMR446 in the US (where PMR446 is not used) this antenna proves somewhat suitable

And here is the final result, the radio now has the new antenna fitted, and seems to work fine and has survived it’s operation
Now to see how good it really is
73

Midland Base Camp446, the “Swiss army knife” radio

Now I just added a new radio to my motley collection of radios, the Midland Base Camp446, which is a “Swiss army knife” radio, or so I think anyway.  What makes this radio different from most PMR446 radios is that it is equipped with a flashlight, USB charging port, medium wave and VHF broadcast reception, VHF marine band reception, and a dynamo charging system to charge the radio or anything connected to the USB charger port.  It also features an alarm clock and Morse code function to send signals using the flashlight. It comes with both a home charger and car charger, a shoulder strap, and a Midland branded speaker/mic for ease of use, I tested the speaker/mic with my other radios with a 2-pin standard connector, it worked with my Intek MT-5050 but it did NOT work with my Intek H-520 (the transmit was jammed on with the mic connected), the radio features a high and low power setting so as to save on the battery if you are only communicating over a short distance, it is simple to operate, the volume and power control is rotary, which I like in a radio, the tuning/channel change control is a momentary rotary control, turn right to increase channel, left to decrease, a 4 position switch selects the band, a 2 position switch below that selects the battery type, and a 2 position switch below that turns the light on and off, on the right hand side is the dynamo crank, this can be turned clockwise or counter-clockwise to recharge the batteries or phones, MP3 players, iPods, GPS systems, and PDAs that may be connected to the USB socket in the left hand side, the left hand side also features the flashlight, the speaker/mic socket (2-pin), and the charger socket, the rear has the antenna, which folds down, a very large battery box for both the supplied rechargeable battery pack and normal AA sized batteries, all in all a good radio.

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Mods:

Note, For information only, I do not recommend or encourage modifying PMR446 radios, you do so at your own risk

This radio can be modified for increased power output (3 watts), and increased channels (LPD433 on the PMR446 only model), or locked to LPD433 only, or PMR446 only
Inside the unit you need to locate 3 jumpers, these are JS4, JS17, and JS16, the settings are as follows

JS4	JS17	JS16	PMR446 settings	LPD433 settings
0	0	0	500mW H/10mW L	disabled
0	0	1	3W H/500mW L	3W H/500mW L
0	1	0	500mW H/10mW L	500mW H/10mW L
0	1	1	3W H/500mW L	disabled
1	0	0	500mW H/10mW L	10mW
1	0	1	500mW H/10mW L	disabled
1	1	0	disabled	10mW
1	1	1	disabled	3W H/500mW L

EDIT: I discovered a service door (it’s an unmarked piece of thin black plastic) in the rechargeable battery pack compartment during a routine security mark, all 3 jumpers, plus a cut 4th jumper were present, the 3 jumpers were closed, in the above diagram, 0 means do NOT cut, 1 means cut, the order is unknown jumper (already cut by Midland), js4, js17, and js16, don’t touch the first jumper.
The picture below shows the location of the jumpers behind the service door

The 4 loops apear to be steel wire, so you may need some very sharp cutters to cut them, to put the radio back how it was just reclose the 3 loops, leaving the left-most one as is

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I will make a short video demonstration of this radio in the coming weeks, stay tuned
73

Beginner’s guide to PMR446

I thought I’d begin with this, a beginner’s guide to PMR446
PMR446 is a (normally) short range two-way radio service that is license exempt and used throughout Europe, it is divided up into 8 simplex channels (one channel for communications both ways), and with an option for 38 CTCSS tones and DCS on some radios, though be aware that it may say in the instructions that CTCSS increases privacy, it, in actual fact, keeps out transmissions not sending the same CTCSS tone, the receiver will still receive the signal, you just won’t hear it
The range of PMR446 can be anything up to 6 miles in open areas, more if the conditions are right to a few meters in built up areas, however last weekend I managed 0.31 miles (about 1/2 a kilometer) on a pair of old and cheap PMR446 units in a built up area, I wasn’t expecting even that because these units (Binatone EK1000) are very compact, and have a shorter antenna compared to most PMR446 units on the market, my DX day later in the year will involve the use of a Binatone Action 950 as opposed to the EK1000
PMR446 radios are made to meet the following specifications
Transmit power: 500mW EIRP (Effective Isotropically Radiated Power)*
Antenna: Integral*
Channels: 8*
Form Factor: Hand portable
*= on some units these values can be changed outside of PMR446 parameters, you do so at your own risk, I don’t encourage the modification of radio equipment outside of it’s type approval
PMR446 channel arrangement

Channel Number	Frequency
1	446.00625 MHz
2	446.01875 MHz
3	446.03125 MHz
4	446.04375 MHz
5	446.05625 MHz
6	446.06875 MHz
7	446.08125 MHz
8	446.09375 MHz

It should be noted that it is not permitted to use PMR446 equipment in the US as the frequency allocations are used for amateur radio, it should be possible however to use this equipment in the US if you are a licensed amateur
There are gateways on both this band and the 27MHz CB band in operation, these use the Free Radio Network client available from www.freeradionetwork.eu, these are located all across Europe, are not repeaters so therefore are perfectly acceptable to set up, unlike repeaters which are prohibited
I can be found on channel 5 with CTCSS tone 5, though I do scan the band frequently, if you send a call I will reply if I hear you
but for now I’ll be back soon