At first you may think "Oh no, not yet ANOTHER Tuner" but a closer look shows this tuner is just a bit different to your run-of-the-mill AM/FM tuners
Look further down in this description to learn about what makes this tuner a bit different
DENON LW/AM/FM Tuner
Analog
Mechanical tuning
Model: TU-710
Made in Japan
1986 release
Classic champagne gold finish
Frequency ranges:
FM 87.5-108MHz
AM 522-1611kHz
LW 153-560kHz
Rear antenna connector strip:
AM: Loop antenna is provided with screw down terminals for an external antenna.
NOTE: for good Long Wave reception, the user MUST use a decent external antenna fit for purpose.
FM: Provision for direct connection of a dipole or similar antenna
Clear, easy to view GREEN/RED dial pointer - normally Red but changing to Green when a station is found
FM stereo Red indicator
Signal strength bar graph meter (6x Green LED's)
Mono/Stereo push switch - forces the audio into mono channel mode AND opens up the squelch when set for FM reception
AM/FM select switch
MW/LW select switch -this only functions when the previous switch is set to AM
SUPPLIED WITH:
AC power lead
AM Loop antenna with leads
COSMETIC CONDITION:
Very clean all round
One mark on the casing top.
Sides, rear are all fine
Front panel is clean and easy to read EXCEPT the frequency dial!!!
SPECIAL COMMENT:
I took the cover off (I like to look around inside!) and looked very carefully for any signs of a front panel lamp/LED (s) to provide background lighting to the frequency scale - THERE IS NONE AND NEVER HAS BEEN!
I love the cute dial pointer that changes from Red to Green upon tuning "into" a station but the background scale is difficult to read because there is no backlight. This was a big design problem Denon!
Sure, a couple of low level white/yellow backlights could be quite easily fitted but I certainly never went to that sort of trouble - but others might like to do something about this issue.
Absolutely no dents or dings!
All labelling is un-damaged
All knobs/buttons are clean and without marks or damage.
Australian standard AC plug/lead is fitted
HISTORY AND GENERAL WAFFLE ABOUT LW:
This one was part of my communications "monitoring" setup, I used to listen to everything from LW right up to the GHz satellite downlinks plus a bit of P25 GRN system scanner and sometimes transmit on frequencies (where permitted a.k.a Amateur Frequency Allocations - VK2DWF) Those days are now well gone (too old, not enough time) so I must find a new enthusiast who might like to listen to Long Wave in Australia.
PLEASE NOTE: I get asked this ALL THE TIME
This tuner is ABSOLUTELY useless to listen to the likes of NSW Police! NSW Police (and other agencies) use the Motorola P25 system in conjunction with APCO25 encryption, which uses rolling "keys" to decrypt the radio communications. This tuner will not tune the frequencies used by these essential services but more importantly cannot decode the transmissions - in fact ANY NON-AUTHORISED RADIO COMMUNICATION EQUIPMENT cannot decrypt those APCO25 encoded transmissions - that's why they are encoded, so you cannot listen to them! Even with a P25 scanner you will only hear a strange burst of noise and nothing intelligible at all because your scanner cannot decode the transmission. Even if you had a "key", the next day it would be useless as the key changes constantly. You can hear some NSW Police channels online but only because the NSW Police want you to! If anything dramatic is happening, encryption will be used and you will hear no more.
Back to this TU-710 tuner. I didn't actually use the AM/FM functions very much at all but kept the tuner running on LW - something just a bit different although many people would find it VERY boring!
LW (Long Wave) frequency range is below your normal AM stations and very few "modern" receivers can listen to it. Why! In Australia, there is no music, there is no talkback (even the News) but it is full of NDB's (non-directional navigation radio beacons). These are transmitters located throughout Australia and their purpose in life is to send signals that are used by aircraft for positional navigation. Each beacon is designated a callsign which is most often sent in the form of Morse Code (dots and dashes sent as tones)
Another possible listening target might be NAVTEX transmissions, a section of Maritime communications although this is data based (very slow data at 100 bits) but you will need external equipment to decode the BFSK signals. You would be listening for transmissions external to Australia, specifically the Asian region (we don't use NAVTEX now, having chosen satellite instead)
Here are some of the Asian NAVTEX stations on 518 kHz
It is noisy down in Long Wave land (lots of atmospheric crashes and bangs) but some folks get a kick out of trying their hand at NDB DX (trying to hear the furthest away NDB from their location) - a side benefit is that you can also hear thunderstorms in your area (or approaching) as this storm activity creates MASSES of atmospheric noise on the tuner.
So I am really promoting this tuner for its Long Wave abilities, that doesn't mean it will not work on the "normal" AM/FM but in these frequency ranges it is nothing too special, although I have seen audio people comment that they like the sound of the tuner on FM very much. Just depends what you are "into"
NDB Callsign RIC on 347Khz
Here is a list of NDB's that can be found around Australia
TESTING:
Powered up, it's alive!
Display is dull, dark and unspiring with the only glimmer of life being the Red pointer. Please see my notes above about this
Buttons all work as they should - note that there is NO memory system
Tuned in stations across FM, MW & LW bands - the stereo led indicates correctly, signal strength meter is working fine.
Keep in mind when listening to FM that if you have the STEREO/MONO button out, there is no sound at all between stations - auto muting takes place until "opened" by a station of sufficient signal strength.
Based on experience with many many tuners in this location, the sensitivity seems fine and "normal" but nothing exceptional though.
The audio on the other hand sounded VERY GOOD, particularly on FM - nice if listening to music is your thing.
No problems receiving the NDB callsign RIC although this is as it should be, Richmond NDB is only about 20Km from me! Of course if you were to become a serious LW listener, a communications receiver with more precise frequency control, BFO and some sort of ANL would be much preferred but this tuner does the LW listening function as well as can be expected when it doesn't have all the features of a purpose built comms receiver.
