Apparato UHF ad uso civile
Info da: http://www.wa7x.com/t
The Kenwood TK-809(T) is a radio bearing the Kenwood brand name that has recently appeared in large numbers on the surplus market. Both internally and externally, it is very similar to the TK-805, sharing many of the same major components having a somewhat similar board layout - but these differences are large enough to make to make TK-805 technical data of limited use.
"What can I use this radio for?"
Not a lot is known about this radio: It does not bear any FCC certifications but rather various EU (European Union) insignias implying that it was intended largely for that market.
For this reason, it is not legal to use this radio in the United States on business frequencies or for GMRS purposes. While this radio does appear to easily to meet the technical specifications required for type acceptance, it does not officially bear this designation.
The only possible legal use to which this radio may be put in the U.S. is in the licensed Amateur Radio service on the 70cm amateur band.
Miscellaneous info on the TK-809:
- Power output: 25 watts (typical) maximum. This is (internally) adjustable down to 5 watts or so.
- Frequency coverage: 438-470 (for the "T" version. It will not go beyond this range.)
- Designed channel spacing: 12.5 KHz. Read more about this below.
- Factory deviation setting: +-2.5 KHz. Read more about this below.
- Tone signaling capability: Subaudible (e.g. CTCSS or PL), DPL, and several others. This radio has decoding capability of at least some of these formats.
- Measured receive sensitivity: Better than 0.25 microvolts - typically 0.15 microvolts
- Antenna connector: N-type on the end of a short "pigtail" cable.
- Squelch control: Internally adjustable only: You have to set it and forget it.
- Microphone: None included, but a number a different Kenwood microphones may be used for typical operation.
- Mounting bracket: A slide-in mobile mounting bracket is included: The radio is secured by a screw on either side.
In (apparent) accordance with newer EU regulations the TK-809(T) was designed for 12.5 KHz channel spacing. What this means is that the deviation is set to +-2.5 KHz out of the box and the receiver's IF is designed accordingly. A simple potentiometer adjustment can set this radio (and the subaudible tone) to a level appropriate for the more standard +-5 KHz deviation.
What this means is that (technically) this radio's IF is too narrow for use with standard +- 5 KHz deviation signals. In practical fact, this isn't too much of a problem except with signals that are somewhat overmodulated already, in which case squelch clamping may occasionally occur. A number of local amateurs have been using the TK-809 and have had no complaints.
Programming the radio:
This radio may only be programmed via a special serial interface and using a Kenwood program: Information on both of these may be found on the web with the appropriate search. This program, unfortunately, is rather cryptic and nonnutritive, so programming various features such as subaudible tone and various other functions may elude the inexperienced user.
While this radio has a number of scanning and channel bank features, these may only be accessed via the recommended microphone - assuming proper programming. Using a generic microphone and the limited front panel buttons, a small subset of these features may be used. If, however, all you need is a very simple radio (e.g. turn the knob and talk/listen) for general use, the simplest microphone works very well.
This radio is "channelized" - that is, any frequencies used must be programmed into the memory and this means that even a "repeater reverse" (e.g. "talkaround") must be programmed as a separate memory. If you wish to QSY to an arbitrary frequency or use a different subaudible tone, you are out of luck unless it just happens to have been programmed in the radio. Being that this radio has at least 100 available memories, most users' needs may be accommodated.
The radio's display is a 5 digit 7-segment LCD with no accessible decimal points. Because it is channelized, what shows up on the display could either be a channel/bank number or (as is recommended without the fancy microphone) a label.
While it is possible to program alphanumerics to be displayed, the fact that standard 7-segment displays are used (look at the number "8" on a calculator - that's a 7-segment display) the ability to display various letters using just these segments is extremely limited - and some letters' representations may not even resemble what they are intended to be.
Amateur radio operators are usually happy to just display the frequency instead - or a portion of it. Not having a decimal point available is a bit awkward, but one can substitute the "underline" or (or some other line/symbol) and make do. A typical example of this would be representing a frequency of 446.500 MHz as simply "6_500" - simple, and to the point.
"How do I get my TK-809 programmed?"
Exactly how to program this radio is beyond the scope of this document. If you are interested in some details or would like to find out how to have this radio programmed, send email to the address below.