TTi PMR-506TX/MH PMR-446 Radio Review

TTi PMR-506TX Drop In Charger 2
TTi PMR-406TX Radio

The PMR-506TX is another new radio from TTi in Korea. Whilst there are many new PMR radios out there to choose from there are only a few that offer anything different. In this case the 506TX is one of the slimmest and lightest PMR radios on the market and certainly won’t weigh you down. There are two different packages available containing this radio. One is a standard PMR radio, the 506TX with desktop drop-in charger and the other, the 506MH is specifically aimed at Motorcycle riders as it contains the necessary hands-free kit for both rider and passenger and allows the radio to be used as an intercom device.  In both cases the radio contains a built in lithium-ion battery pack which is an excellent choice for long battery life between charges and doesn’t suffer from the memory effect of other battery technologies meaning you can “top up” the charge of this radio at any time you wish.

The drop-in desktop charger is supplied in both kits and comes with a lightweight plug in mains adapter. This charger is excellent, it even comes with two screws in the package so you can wall mount or fix permanently to a desk if used in a business situation. It also stops the device from going missing if used by a number of different members of staff! The radio simply clicks into the charger and the charging process begins immediately. Whilst the radio is charging the charger has an indicator which illuminates in red and once the battery is fully charged this will change to green. It appeared to take about 4 hours for the review radios to charge.

The TTi PMR-506TX is very lightweight, in fact so light that when I placed it into my jacket pocket I almost forgot that it was there until I heard some activity on the channel I was tuned into. At just 78 grams it is even lighter than most mobile phones. For a motorcycle rider any additional weight is always a consideration and I’m pleased to say that the radio is light as a feather, you’ll just have to be careful not to loose it! The radio has a feel of being solid and well built despite its minimal weight. The antenna is only 5 cm long so shouldn’t make a hole in your pocket either.

TTi PMR-506TX in the drop-in charger

Switching on the radio reminds me of several other TTi PMR products and if you have used any of them previously you will feel at home with the 506 straight away as the menus are very similar. The front panel buttons are minimal as you would expect on a radio of this size but everything is easily accessible. The M button is the one that does almost everything, this is the menu for the radio and allows you to select channel number and privacy code options (CTCSS code). There is no DCS in this radio, only CTCSS but it covers the common 38 privacy codes used by almost every other PMR-446 radio so should be very easy to get working with all other brands. There is also the option of not using any CTCSS so you can transmit “in the clear” so you will hear all activity on the channel.  The LCD display on this unit is large and well lit in green back-lighting considering the size of the radio it works very well indeed.  The display shows everything you need to know at a glance and should work well for night time use too. Every Time you press a button the display illuminates and this also happens when you transmit.  A nice bonus feature of this radio is a built in bright white LED torch! Pressing the small button located on the side of the transceiver underneath the PTT button will make this top mounted LED light and you have a small but very powerful touch, very useful in total darkness for locating a keyhole, for example. This works independently of the radio and can be left switched on whilst transmitting or receiving if required. Another press of the touch button turns it of again.

Volume on the 506TX is very simple to control, the up and down keys on the front of the unit allow seven different levels and the same keys control the selection of the menu options when the M key is depressed.

A number of other options are available from this radio including the usual ones such as a roger beep for the end of your transmission and dual watch where two channels can be monitored for activity, VOX (voice operated mode) which has become commonplace on many radios, the ability to turn the keypad beep on and off, an intercom mode which will be of particular interest to motorcycle riders as it allows the rider and passenger to chat with each other without using two radios but the most surprising feature of the 506TX for the price is the addition of a voice scrambler. Not many radios at this particular price point come with a scrambler but they can be useful when you need some additional privacy and want to stop casual eavesdroppers. At this stage it is worth pointing out that scramblers in PMR radios do not offer any security against people who are determined to listen to your conversation such as radio enthusiasts. Sure they will stop the average person from listening to your conversation on other PMR radios but a radio enthusiast with a computer or similar set would be able to listen in without any issues. The reason for this is that PMR-446 radios only offer a very basic scrambler service called “analogue voice inversion scrambling”, this basically changes low pitches to high and vice-versa so anyone listening on a normal radio will hear squeaky/scratchy voices. The other thing to consider is that anyone else with the same make of radio could also descramble your transmission easily by switching their scrambler on too.

TTi PMR-506TX Drop In Charger 2

Generally scramblers offered in PMR-446 radios from different manufacturers do not work together properly so if you want to use this feature you are best buying all the same type of radio for your group of users. For example, I tried the scrambler on the 506TX with the one in a Motorola XTNiD radio and whilst it did work to a certain extent it made the other persons voice sound a little like Donald Duck which was amusing but not ideal for long term use, I tried all three different settings on the XTNiD but setting “2” sounded the best.

Going back to other features in the 506TX there is also a room monitor, sometimes known as baby monitor, in this mode the radio will transmit on a given channel every time noise is picked up in the immediate area and there is also a scan facility allowing the user to scan all 8 PMR channels for activity so if you are just interested to see which channels are in use in your area then simply hold down the CP/S key on the front of the radio and away it goes stopping for about 3 seconds whenever activity is discovered and then resuming the scan when all is clear again. Whilst in scan mode any CTCSS code is ignored so you will pick up any and all activity on all 8 of the PMR channels. There does not appear to be a facility to lock out any unwanted channels as there is on some PMR radios.

TTi PMR-506TX Standard Package

The 506TX also has a call button in red on the front of the radio, pressing this allows you to send a ringing tone on the channel to any other units. There are 3 different styles of ring-tone available from the menu options. These are pretty much standard these days on a good PMR radio and can be effective if not over-used by kids!

Voice operated transmit is a big feature of this radio, especially as it is marketed as a Motorcycle compatible PMR radio. On the very top of the radio there are two jack ports to connect up external headsets and microphones. There are many optional accessories available for the TTi series of PMR radios in the standard 2.5mm/3.5mm jack plug combination. If you opt to purchase the Motorcycle package then two headsets/mics and a double jack plug adapter are supplied. These can turn the radio into an intercom system between rider and passenger – the option for intercom can turned on or off inside the menu system. Alternatively a single headset configuration can be used by the rider of a bike and used in the VOX mode to allow them to chat with other bikers using a similar piece of kit. This is clearly a very useful piece of equipment for motorcycle instructors too when out training on the road.  The VOX setting on the TTi allow for both high and low levels and these can be set via the simple menu system and the up/down key on the front of the radio. The VOX facility can be used with or without headset but it would only be of limited use without the headset facility but I can confirm it works with the built in microphone.

TTi PMR-506MH "Motorcycle Package" complete with headsets

The rider/passenger headsets supplied for the review are comprehesive and would suit any biker looking for a PMR radio solution to fit inside a helmet. Quick release connectors are supplied along with self-adhesive earpieces and boom-mic with windsheild to place inside the helmets for both rider and passenger. The TTi kit supplied by Sharmans for the review contained two headsets and this allows the kit to be used as an intercom system too.

So how did the 506TX perform on air compared with other similar PMR radios. When I first saw the radio I did wonder if the reception would be any good considering the minimal size of the unit, particularly looking at the size of the built in speaker but I need not have worried because during the tests I found the volume from this little radio was suprisingly powerful and I even ended up turning it down on the middle volume setting. The received sound was crisp and clear without too much bass which you would expect from the size of the unit and the transmitted audio from the 506TX was also crystal clear when used with another 506TX and my much larger Motorola XTNiD radios so top marks to TTi for engineering a good sounding PMR radio. The built in mic worked really well provided that you talked within 5 inches of the front panel.  This is the best sounding little PMR radio I have ever tested, don’t be decieved by its size! Another feature that TTi has managed to cramb into the radio is a receive “compander”, this claims to reduce background noise on the recieved signal, this seems to work by limiting top end frequencies from audio to give a smoother sound. This can be toggled on or off by pressing the CP/S key on the front of the radio. It’s down to personal preferences as to wether you like the sound of this or not but the option is there if you wish to try it.

As you can imagine, the size of the radio limits the size of the PTT (transmit) button on the left hand side of the radio. It is very small and could take some getting used to although after I had used the radio for a few minutes it became very easy to find the button and press it with my thumb. It had a positive feel to the rubber key and a transmit icon on the display is shown to confirm that you are in the transmit mode.

TTi 506MH Motorcycle Kit
Here is the kit supplied with the 506MH version of the radio. Comprising of ear pieces with self adhesive to be installed inside the helmet, boom microphone, quick release connectors and manual PTT button for attaching direct to the handlebars on the bike. The other adapter towards the rear of this picture is for use with the intercom facility. With the 506MH you get two identical headset kits as pictured above.

Battery life on the radio seemed excellent with average all-round use. A battery symbol on the LCD display keeps you informed of level in three stages. Likewise other symbols can show the status of the scrambler, intercom, beep/roger beep and Intercom. The only thing that might concern some users is the lack of a user replaceable battery pack but this is no different from many other lithium based electronic products including the very expensive Apple iPhone! I am sure TTi would be able to replace the battery in these units for a reasonable cost in the future but with average use most people will get many years from the radio without having to worry about this.

TTi PMR-506TX with LED torch

Reception quality and sensitivity from the small antenna seemed to be above average when compared to other other similar priced PMR radios, I put the radio into scan mode and had a listen around the band. I was soon hearing a variety of stations and the radio seemed to pick up as well as some of my other PMR-446 radios and in some cases, even better. For the size of the radio I’m really impressed with what I can hear and the reports I got back from the 506TX suggested that the audio quality was very clear.


To conclude this review I would say that the TTi PMR-506TX scores an excellent rating for anyone looking for the smallest PMR radio possible at a reasonable price and packed with features normally found on much higher-end radios. The scrambler is a welcome addition to the feature set and the flexible VOX options and the rider/passenger headset, microphone and intercom features are excellent and add real value to the kit for travellers.  The performance of the radios out and about was great and they exceeded my expectations for the size. I’m sure this kit will be popular with the Motorcycle enthusiasts and riding instructors.

Sharman Multicom Logo

The reception quality and sensitivity of this radio is particularly notable and the built in microphone provides great transmitted audio with exceptional clarity. It really does prove that it is possible to build a smart looking, ultra thin radio without the compromises in performance that some models of the past have shown.

I would like to thank Murli at Sharman Multicom for supplying the radios for this review, both in standard format and motorcycle packages. The radios should be available now at all good TTi dealers across the UK.


About TM1 78 Articles
Simon is the founder and owner of the TM1 website. Since 1999 he has provided the online community with a place to meet up with like minded radio enthusiasts and discuss projects relating to the hobby and a large number of equipment reviews and resources totally free of charge.


  1. Does anybody know – when in Intercomm mode, is it still possible to use the radio as (waaait for it!) a Radio?

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