As the signal from this feed is only capable to provide what UVB-76 does, the broadcast has been more static lately than anything else. It is still good for one thing, and this is to have people exploring further in shortwave mystiques.
As the first and only genuine thing is to buy your own receiver, I am now writing a short survival guide in radio receivers world, so that one would be able to end up with more or less satisfying purchase.
At the beginning there are some technical aspects to consider, the most important of which is "what do I want to listen at".
While the spectrum is full of all sorts of signals starting from about 30kHz and ending up above 20GHz today, the most rewarding was and is shortwave. The higher frequency bands are fun if you know what to do, but if you are reading this tutorial you might seriously consider starting from shortwave, get accoustomed with basics and only then move on to higher bands.
The first aspect to consider at the receiver is what frequency band it covers. For shortwave work you shall aim at least with the receiver with the coverage from 510kHz (low end of the commercial midwave (MW) broadcasting) and ending at 28MHz (upper end of the Citizen Band (CB) free shortwave frequency). Below and above is nice to have but not mandatory.
You shall also check, especially on a cheaper "travel" or "world band" receiver type of radios (the ones what resemble ordinary pocket- or clock radio but have more frequency bands on them), that they will not have gaps between band selections. Many of them have blind spots between different shortwave bands and you will be disappointed if everybody will be talking about the station you will not be able to pick up as it "falls between" your frequency selection.
Choose one with contignous coverage from at least 510kHz to 28MHz.
Second important aspect is the modulation what you want to receive. On shortwave band two modulation methods are dominating:
AM (amplitude modulation) and
SSB (single side band). Check the links, it will explain in detail the technical background.
Most of the commercial broadcasts are transmitted in AM modulation, and there is a pitfall you may find yourself from, if you have acquired el cheapo clock radio with shortwave capabilities. It is likely oriented towards commercial radio stations and does not support SSB.
What you are interested of is "all the other stuff" besides commercial broadcasts and this is predominantly happening SSB mode. SSB itself divides USB and LSB (Upper Side Band and Lower Side Band) and you are going to need both. There are some stations on a shortwave band operating on FM (frequency modulation) and DRM (digital), but this is still marginal today.
Some of the more advanced radios also have a special mode for morse code, named CW. While this makes reception of the morse code more effective from interference and morse perspective, it does not mean that you can not receve morse in AM or SSB mode. You can, but it is just not that clear signal (there are lot of other aspects regarding morse and digital transmissions, but this takes another article).
Choose one which as at least AM and SSB demodulation.
Now that you have your basics, we can start choosing the receiver.
As far as shortwave goes, you have five types of receivers to consider:
- "travel", "world band" etc. small radio receivers what are intended for listening to the commercial shortwave broadcasts at household or while traveling.
- Professional, semi-professional and amateur communication receivers and scanners
- Vintage Shortwave receivers
- Software Defined Radio (SDR) receivers meant to be used in combination with your computer and soundcard
- Internet sites offering remote access to radios of others around the world.
This blog entry will get too long if I go in-deep with these, so I will cover all except internet radios briefly and make a separate article about the internet listening and SDR.
There will also be a separate article about the antennas, so lets just stick with te long 10+m/30+ft wire before that.
"Travel" and "World Band" radios
These are the most simplistic (and inexpensive) variety of receivers. While the brand names like Sony and Grundig are making some, the eBay is crowded with all sorts of more or less noname types. I havent tested any of them, but looking at the eBay now there are several what satisfy the initial selection category we had above. TECSUN PL-300WT $45.99; Sangean ATS-505 for $AU169; Sony ICFSW7600GR $185 (expensive, but brand costs); ANJAN DTS-10 $112.99; just to name first four what popped up.
It is hard to tell what is good and what is not as they are all rather basic. External antenna connector would be nice, but if not, you can fetch a long (more than 10m/30ft) wire, drag it somewhere (preferably outside the house and as high as possible (above 3m from ground minimum)) and wrap the other end around the telescopic antenna the radio has. Recording output would be nice, but absence is not the end of the world.
Be sure tho that it would work from something other than batteries as well - monitoring some frequency means that you will have the receiver on and tuned 24/7, so it is useful to have it take its power from mains
outlet.
Professional, semi-professional and amateur communication receivers and scanners
These we can divide further as portable/desktop and as receivers/trancievers. Transiever means, that it has also a transmitter built in, what you are going to need only if you want to beome a true radio amateur.
The basic selection criteria stands for these as well - I have seen radios what do not do SSB ans still call themselves a scanner.
The choice between portable and desktop is yours to make. I do have portable ICom R20 and I am very satisfied with that. However, I also possess vintage Russian R-250 tube shortwave receiver from year 1952 what weights 60 kilos and has more than 20 tubes in it. And this has given me some best moments on a shortwave.
The rule of thumb is, that all other parameters equal, desktop is better. The reason is, that it has more room for all sorts of tuning components (capacitors, coils, filters etc.) as well as for physical layout, therefore the design can be more straightforward and effective.
You should expect to spend around $200 to $1000 plus the shipping of the 6-10 kilo item.
Looking at the moment in eBay there is not much choice at the "by it now section", with the exception of two lots of ICom R71E for $180/$185 (good pick!).
Don't know if the fellow readers of this blog and forum have already been raiding the eBay, but the choice seems very limited at the moment. The things to look for would be Kenwood R-1000, Yaesu FRG100 and likes. Search strings to us would be "communications receiver", "Yaesu FRG", "Kenwood R", "Icom R". If you need one today, go for the ICom R71E, it will make you happy!
A word of caution tho - desktop receivers may time to time (well .. once after 5-10 years that is) need some internal tuning and calibration, so befor buying one try to figure out if someone deals with that stuff in your area. It is not that the radio goes mute otherwise, but the extra bit of sensitivity and signal quality can be lost over time.
Vintage Shortwave receivers
Like said, my vintage R-250 is a wondeful piece of equipment! There is something about the tubes what makes the feeling of the "signal really getting to you" a different experience for me. If you have some radio skills, try to find one what would work (repairing one takes a qualified radio technician, but even operating one needs some skills) and go for it.
Note, that some older Kenwood and Yaesu solid state receivers are today advertised as Vintage in eBay, but I would not consider them a "true Vintage" although some of them are 30 years old.
If your first shortwave receiver is a tube one, you will fall in love with it even if its a regular commercial broadcast radio from 50-s. There is not much technical suggestions about it - military ones have better frequency coverage and do have SSB, however, the regular old household radios will be equally daring, although unsuitable for number stations work (for the lack of SSB and having large gaps between tuning bands)
Software Defined Radio (SDR) receivers
These are meant to be used in combination of your computer and soundcard. Some, like ICom R100 and likes, can be used without the computer as well.
SDR principle is, that radio signal is not fully demodulated to audio in the receiver, but the signal is fed into computer half-way and all the audio processing is done in the software.
The UVB-76 Repeater is using SDR radios what cost $18 as a kit. If you know how to use these you will get amazing results, but only if you know what you do. The advantage of using the SDR is the flexibility of the signal processing - you can tweak with the decoder parameters much better than most of the desktop receivers allow.
Important thing is that you will get he visual control over the tuning of the receiver with the SDR! As you all have been getting familiar with the WinradHD screen captures and little waterfall window the uvb-76.net has, you will get the idea. If you like messing around with the computers on every occasion, this is for you. But more of it in the next article.