Pocket DAB Radio DXing Possibilities

An addendum to Pocket DAB Radio Sensitivity

This article was originally written in July 2016. Since then, two new radios with manual tuning capability has been tested alongside the others and the passage rewritten. The original article can be found here and here.

This addendum looks at the manual tuning facilities of the pocket DAB radios tested and whether they could be useful for locking onto and identifying out of area DAB multiplexes. One useful function is for DAB DXing — being able to receive and identify distant DAB multiplexes, particularly during periods of unusual atmospheric conditions.

A recent example of this with FM and DAB in the UK happened when numerous Dutch, German and Norwegian stations and multiplexes had their signals propagate over the North Sea during a period of high pressure in June of 2016. Whilst this had the effect of wiping out local and national UK radio stations, it also allowed strong FM and DAB reception from the aforementioned European countries for a period of time.

Out of the twelve pocket DAB radio sets tested, seven of them contain a function to allow manual tuning. This function is important to allow a person to view the signal level of a multiplex to maximise reception prior to locking onto a signal and being able to decode the Fast Information Channel (FIC) to identify the multiplex, services and other important information the receiver needs.

The Radios

Azatom Pro Sports S1

The manual tuning option for the Azatom is within the main menu. There is a curious bug within the manual tuning option for the Azatom. On low strength signals, no measurement will appear on the signal meter. The multiplex name will appear next to the frequency for a brief second before disappearing.

Sadly, this bug cannot be fixed with a firmware upgrade, as the firmware is not upgradable. As a result, this radio is crippled for DX use.

Lava Kaliko

As with several of the radios, the Lava employs blind manual tuning. All you will see is the message as illustrated to the left. If the radio has detected a signal, it will display the message for a few seconds more and then tune to the first station on that multiplex alphabetically. This implementation of manual tuning make it difficult for DX use. Worse still, the signal meter in the top right of the display is no indicator of the currently tuned frequency, rather the remnants of the last tuned stations signal strength.

Another frustration of this radio is the unresponsiveness after it locks onto a station. You have to wait several seconds before you are able to register any button presses. Worse still, this can happen often on weaker signals. All this makes this radio frustrating to use.

Logik LHDAB14

The Logik LHDAB14 has no telescopic aerial and employs blind manual tuning. This means that you have no ability to fine tune the radio by moving it about until you hit a sweet spot for signal. Once it does lock onto a signal, it displays the multiplex name on the display.

The situation regarding blind tuning makes this radio somewhat difficult for DX usage.

Majority Petersfield

As with the Logik LHDAB14, the Majority Petersfield has no telescopic aerial and also employs blind manual tuning. As before, this makes it difficult to determine where best to place the radio in order to gain the strongest signal. As with the Logik, the use of blind manual tuning makes this radio difficult to use for DXing.

One useful and welcome function the Majority Petersfield does have over its competitors is the ability to view the stations on the tuned multiplex, including data services, by pressing enter, using the left and right buttons to scroll through the stations and pressing enter to tune.

Majority Petersfield Go

Unlike its predecessor above, the Petersfield Go does deploy a signal strength meter. However it suffers the same issue as the Azatom where at low signal strengths, it will only briefly flash the first letter of the multiplex and show no signal strength on the meter, making it just as crippled for DX use. And unlike its predecessor, you cannot view the stations on a tuned multiplex after it has locked onto a signal.

Reka DB-355

Sold through Aldi in April 2018, this radio uses the Frontier Silicon Siena module. It employs a signal meter to show how much signal is being received by the radio. In order to lock onto a signal, the signal has to meet or exceed the larger square within the meter. Unlike the Azatom and Petersfield Go, the multiplex name will remain after the signal locks and scroll across the screen.

Roberts Sports DAB 2/6

Spot the difference. The Roberts uses the same screen as the Azatom — the only difference being is that the Roberts has a much nicer front panel for its case (as you’d expect for the price). The manual tune option does register as expected with the large square being the recommended signal strength for error free reception. As with the Azatom, the multiplex name when locked appears next to the frequency. Unlike with the Azatom, it will stay on screen and scroll regardless of signal strength. At which point you can exit the manual tuning option and view the stations you picked up on the station list.

Singstek HRD-101

Also sold under the Exmax and several other brands, this pocket radio uses a signal meter for its manual tuning function. When it locks onto a signal, it will after a second or two, scroll the multiplex name across the screen.

Sony XDR-P1DBP

The DAB manual tuning is accessed via the menu button on the front panel. You are then presented with a list you select using the rocker on the radio. If the radio cannot find a signal, the words “Service not available” scrolls on the screen. If the radio finds a signal, “Tuning…” flashes on screen and the multiplex name will appear if it locks onto the FIC.

As with the Majority Petersfield, you are unable to fine tune the radio by moving it around whilst it is tuning.

VQ Blighty

The VQ Blighty as with the Majority Petersfield, does not have a telescopic aerial. As with the Azatom and Roberts, the manual tune option is in the main menu. Unlike those two radios, the signal meter is replaced with a percentage — more accurate (a scale of 100 as opposed to 15) but the principle is the same. Other than that, the radios manual tuning option works in the same way as the Roberts.

Yaakin WalkRadio K1

The WalkRadio K1 employs blind manual tuning. When the radio detects a signal, the ‘Tuning…’ text appears on screen and remains for as long as it can detect a signal. Once the radio locks onto a signal, it will tune to the first channel on the multiplex. It is the only radio on test which will not display the name of the multiplex it has tuned to.

One interesting thing to note with the WalkRadio K1 is the inclusion of a fully featured signal status option. It will tell you the bit error rate, a received signal strength indication, the signal to noise ratio, MSCBER and CER of the currently tuned station.

The test

Each pocket DAB radio was allowed to use both its telescopic aerial (if available) and headphone lead to attempt to detect and lock onto out-of-area signals:

The radios were tested in several areas and the results logged onto a table. Also included for comparison purposes is the Wintal DAB10B, a portable DAB+ radio described as a “DX wonder machine”.

The Azatom, Lava and to a lesser extent, the Yaakin struggled with low strength signals, only picking up the strongest of the out-of-area signals. Due to the aforementioned bug, the signal meter of the Azatom never showed any signal but did lock a signal (hence its red detected rating but its green locked rating). Most radios detected the stronger out of area signals and even detected distant signals. The VQ Blighty and the Singstek were the only pocket radio which locked onto one of the two weakest multiplexes, the Derbyshire one for the VQ Blighty and the Leicestershire one with the Singstek. Although the Roberts just crept ahead of both when it came to detecting signals.

The Sony showed that it can perform better using its telescopic aerial, beating the Majority in these tests when in previous tests using just the headphone lead, it did poorly for stationery tuning.

In the previous stationary autoscan tests that I performed, without the help of the telescopic aerial, the Roberts does a bit worse than the Singstek and VQ overall.

Conclusion

Previously, I had decided that the Roberts Sports DAB 2 radio was the strongest. On this occasion, with more intense testing of all the radios and analysing the result, both the Singstek HRD-101 and VQ Blightly narrowly tie for the win with their tuners being able to lock onto a weak signal. However, the VQ was beaten by the Roberts in signal detection and all the pocket radios are still beaten by a portable with a good tuner.

My advice would be to use a portable for DXing if you are mobile. They are more sensitive, the telescopic aerials work better (an dipole or element aerial would be better still but isn’t practical or mobile) and most can easily fit into a bag or large pocket. If you really do need to find weak signals on a pocket radio, the Singstek HRD-101, VQ Blighty or the Roberts Sports DAB 2/6 depending if you have a need for the telescopic aerial should serve you best.

Update (03/03/2017): Added Logik LHDAB14.
Update (29/09/2017): Added Yaakin WalkRadio K1.
Update (10/03/2018): Added Lava Kaliko, Majority Petersfield Go and Singstek HRD-101.
Update (14/04/2018): Added Reka DB-355