A More Expensive, But Not That Expensive, Portable Receiver.

On Ebay I purchased the Tecsun PL-660 portable radio receiver.

The PL-660 covers long wave (LW), medium wave (MW, AM band),  short wave (SW) up to 30MHz, the FM broadcast band (76 - 108MHz)  and the 118 - 136MHz air band (using AM). The receiver is also capable of AM synchronous demodulation and SSB  reception.

The receiver has a digital signal processing demodulator at the IF, and provides two bandwidths on AM reception, and that is a very useful feature, I found.

The receiver has an antenna input jack, specified to work on SW and the FM band. A test shows that it sooks like working in the air band as well. An external (active) antenna for air band reception should provide useful,  an FM antenna should be interesting, too.

The receiver uses 4 AA size cells for it power supply. These can be 1.5V (alkaline) or 1.2V rechargeable cells. I used a set of Eneloop (NiMH) cells, and when fully charged, they showed "battery full" on the indicator, and also tells that I was using NiMH batteries. It stayed like that throughout the testing of the radio.

The air band would have been perfect for my propagation monitoring if the VOR band 108 - 188MHz were included, but I reckon that I could use a low cost SDR for that, if need be.

A quick test showed that the sensitivity of the receiver is quite good on MW,SW and FM, as well as the lower part of the air band. The higher part of the air band seemed to lack gain, maybe due to bad tracking of the input filter.

Speaker quality sounds quite good for its size.

To me, however, it sounds like the DSP (demodulator/IF filter) could be improved, I detected some distortion, especially with somewhat noisy signals, that I never noticed on a fully analog receiver, or with my Icom IC-7300 and similar SDR/DSP heavy radios. OK, I guess that I got what I payed for ;)

I do think that this could be improved in later models. I suspect that it is not possible, or at least not easy, to update the firmware of the PL-660.

The accompanying power adapter, however was a bit of a disappointment. The adapter from US plug to EU plug did not fit into a mains socket, and just bent completely out of shape, no matter how carefully I tried to insert the plug(adapter). So I could simply not test the power adapter. I should probably try to find a suitable adapter, or simply cut the cord with the plug for the radio and make my own 6V power supply for this receiver.

All in all it is a nice and usable addition to my receiver park, I like monitoring a lot of frequencies simultaneously, to get an idea of the radio propagation conditions, be it on LW,MW,SW or VHF/UHF/Microwaves. The previously purchased "cheap" receiver is no more than just a toy, unlike this one. 

Maybe I should make another post or a few, about the setup I use for propagation monitoring. I think, however, that this should be at a later stage when I have completed more of the system.

Local Tropo and Other Propagation on 2m.

 In August we had some beautiful sunny weather, providing some excellent tropo propagation on 2m, and, as reported by others, also on the higher bands. Now we are back to the classical Danish weather, a little bit of sunshine, some heavy rain, even cloud bursts.

A few evenings the local FM channel had S9 signals from distances between 100 and 200km (60 - 120 miles). I refer to this kind of propagation as "Local Tropo", mostly because running SSB/CW regularly provides longer distances than this. 

Don't get me wrong, "Local Tropo" is quite fun, but I prefer working the longer distances, using SSB/CW, and sometimes the weak signal modes, like FT8. 

Mind you, on 2m FT8 is an excellent addition to the arsenal in tropo openings, but for sporadic E the fading in and out is often too fast for finishing a QSO, whereas with SSB or CW the signals can be quite strong for a very short period, then disappear forever, but in that time a QSO can be easily worked with CW or SSB. If the sporadic E lasts longer, the signals are often quite strong for a long time, and it is not necessary to use FT8. 

While this is true for Sporadic E, there might be some longer lasting scatter-like propagation making contacts possible with FT8, that could not be made otherwise, so I cannot totally discard it as being useful. As an example, some weak, slightly longer lasting sporadic E or some scatter mode, extended by tropo propagation just might provide some possibilities for 3-5000km distances for a station location like mine, not particularly suited for long haul tropo (-scatter). Yes I am not located close to an ocean, where really long sea ducts can occur.

Portable Radio on the Cheap.

I have tested the Retekess radio. All analog. Price about 20 GBP on amazon UK. I wanted to play a bit with a modern cheap radio with short wave.

Power supply is a single 18650 cell, rechargeable in the radio via a micro USB connector. I like that. The cell can, of course, be replaced. 

The radio covers FM 88 - 108MHz, SW 8 - 18MHz and MW 530 - 1710kHz.

FM works mostly nicely, tuning is OK, a little fiddly, but doable. Good sensitivity.

MW tuning quite fiddly, sensitivity poor to mediocre. Probably due to a small ferrite antenna.

SW: One band 8 - 18MHz. practically impossible to tune to a station. Sensitivity barely sufficient with the built-in telescopic antenna.

Very nice sound from the speakers, surprisingly good for such a small radio, will probably be in use.

The radio, as it is, is unsuitable for short wave reception, it is essentially impossible to tune it to a single station, mostly due to backlash in the tuning system, and due to covering 8 - 18MHz in a single band. It is essentially just a toy for SW reception.

I might be possible to make it tuneable on SW with a fine tune addition, but the modification might not be fit into the casing.

All in all a somewhat decent portable FM receiver with a medium wave performance only sensitive enough for local reception of strong transmitters.