rnr vi utniur
tJw IctlEiing [nbfjili J
The HOWES DFD4 is an add-on Digital Readout for analogue receivers and transceivers. If you have art FRG7, an analogue FTl01 or a similar [ype oi rig, then the DFD4 has been designed with you in mind. The DFD4 is a frequency counter that can be programmed for any IF offset so it can be used with almost any radio, including the old Government surplus sets. It can also count down as well as up. so it is suitable for "reverse tuning4 rigs too.
To make the DFD4 even more suitable, we now offer the PMB4 Programmable Matrix as an optional kit. Thrs enables you to switch between six different programmed ofise:s, so theDrD* can be used with morethan ont radio, ard to compensate 'ùr IF frequency diiJerences w*en switching modes. Also new is the CA4M "hardware package." This contains a custom made case with pre punched anod zed aluminum iront panel (see drawing above), plus switch, knob, BNC socket* nuis and bolts, etc. to enable you to achieve a high standard of finish for your project.
PMB4 Kit .
CAAM Case 4 Hardware. Ordüfüd floparaieEy
**ri i i IfH an EU ■ l****i ■ llft + i MHIJ ■ -
BUILD A QRP TRANSCEIVER!
To build a transceiver with our kits is a simpfe modular, step by step approach. You can start with the receiver, and then add on the transmitter at a later date if you wish. Various accessory kits are available to increase the facilities, these range From a simple signal meter for the receiver to extra filtering and of course, digital readout. We offer a marching range of "hardware packs" (case, Knobs, etc,) 10 enable your station to look as good as factory equipment! Whether you fancy a single band CW transceiver, or more complex dual band SSB/CWrig, all ihese kits are designed to be within the scope of the ordinary home constructor. The well thought out designs arrd the backing of professionaf RF tesi facilities mean you can build with confidence!
Single band 40 or SOM CW transceiver:
DcRx 40 or DcRi 80 recover kit „,528,95
CTX ¿0 or CTX 00 Transmitter kji . 526,95
CSL 4 300 Hi CW and narrow SSB fi'Eer STG.95
CA 60 M Case & Hardware (40 or 80)-------------------------------------- - S65.95
if ordered separately .. T-S E --TTfTfTTT?? W P I PI I I «W *4 1 ■« ■ ■ ■ ■ ■ !.»■•!■*■■■ ■ ■* ■ ■■■■ ■■■!!■■ ■■*<■■**■ 1 5177.70
To order write or caff:
1 -800-944-3661 - VfSA/MC accepted - Add $4.00 per order tor S & H
"" ASK FOR OUR FREE CATALOG "" Include $1.00 for 1 st class Postage. $2.00 for foreign countries.
Number 7 on your Feedback card
Japan Radio Co., Ltd.
by Bill Clarke WA4BLC 430 Park Ave., 2nd Floor
New York NY 10022 Telephone: (212} 355-1180 Fax: (212)319-5227 Price Class: $4,699
The JRL-2000F HF MOSFET Linear Amplifier
A solid-state, no-turie kilowatt with very advanced features.
Photo A. The JRL-20Ö0F solid-state kilowatt amplifier:
Japan Radio Co., Ltd. (JRC). It is a microprocessor-controlled solidstate no-tune HF linear amplifier capable of producing a solid 1,000 watts output.
When the 2000F arrived it was in a single box and welE packaged inside same The weight of the box was a formidable 78 lbs, and you should be forewarned not to attempt to place this amplifier on anything fess than a desk or surface designed for battleship purposes 1 used two heavy-duty milk crates Due to its weight, this unit cannot be shipped by UPS it arrived at my door via Federal Express (FEDEX).
There is nothing to assemble with the amplifier. It is ready to go as soon as it is unpacked. No tube(s) or trans* former(s) to install. Strictly plug 'n goi
The 2000F comes with a remote hand control, resembling a TV remote control, which can completely operate the amplifier.
For initial testing I used the JST-135 (also from JRC) transceiver. Through an interconnection cable, the 135 converses directly with the amplifier for band/frequency information and control.
The 2GOOF is a complex and modem device, aiihough from the operational point of view it is aboul as simple as you can get. A pre-made cable (optional) is connected between the exctier and the amplifier for control (it contains a few more wires than the usual transmit relay controi line) and a coax jumper for bringing the RF input to the amp.
The antenna system is connected to the four antenna ports on the back of the amp. In the case of this testing I utilized them in the following manner: 80/40 dipoleh Cushcrafl R5 vertical, 160 meter dipoEe, and 80-10 meter Windom. No external antenna tuner was placed in the line.
My first operation was on 75 meters. It took aboul 10 seconds for the amplifier to set itself up for the band segment being operated on, Later return to this segment required only an instant for retuning.
Signal reports were excellent No mention was made of poor signal, low audio quality, reduced power, or distortion. A single 3-500 (1 kW output) tube-based amplifier was used for orhthe-air comparison of signal reports.
Fan noise was not mentioned by anyone. Nevertheless, depending upon physical placement of the amplifier, I believe fan noise could prove to be a problem. However, the 2000F is not the only amplifier to suffer from fan noise. The problem appires to nearly all HF amateur amplifiers,
The typical efficiency of the 2000F appears to be about 60 percent This is based upon meter readings of 22A current at 80 VDC during key-down, with an output of 1 kW.
Antenna control is done by the 2000F. Manual selection is made by pushing buttons on the front of the amplifier Later recall of previous operation on the same (or nearby) frequency will cause the amplifier to select the originally chosen antenna automatically (this can oe overridden by the manual controls)
After using the JST-135/JRL-2000F combination on several bands and enjoying the complete ease of fully automatic tune-up and antenna change, f built connector cables for use with my ICOM 751A and Corsair II The cables must provide, in addition to the normal ALC and PTT lines, a talk-back fine. The latter forces the exciter into transmit during tune-up or after QSV.
Tune-up is still super simple For example, to change from 40 meters to 75 meters you merely push the 2000FTs SET button to sample the frequency of operation (not required when using the JST-135, due to the feedback data line between the transceiver and the amplifier). In SSB mode it is necessary to say a word or two (ie: Kahhhhhr) so the amplifier can determine the operating frequency. Once the frequency =s determined, the 2000F will tune itseff based on prior usage at that frequency
Once the band segments for my favorite frequencies had been programmed into memory, I found the ICOM and Ten-Tec to be nearly as dexterous with the JRL-2000F as is the JST-135, the only difference being the requirement for pushing the SET button and announcing yourself each time you QSY
The ease of the 200QF's automatic tuning and antenna selection brings Ihis HF linear amplifier into the realm of Ihe instant QSY we are all used to with solid-state transceivers, 1 found that when jumping from 14.300 to 3.950, the amptifier tuning and the switching of the antenna tine took aboul three seconds when using the ICOM 751 A. Just punch the new frequency into the 751 s keypad and press ENTER, then press SET on the 2000F and say "ahhhhh," It really is that easy! QSYing with the Ten-Tec took slightly longer as its tuning knob and band selector switch must both be used when changing frequency
Throughout the testing period I was always on the lookout for a glitch to rear its ugly nead. yet none ever appeared. Performance was flawless
The 2000F can be used as an antenna switch: switch and tuner; or switch, tuner, and amplifier Each section is separate in operation but they are linked operationally via microprocessor control.
Switch selections provide for power onfoff, standby, tune (automatic antenna tuner), antenna selection, and set (storage/selection of current operating parameters).
Two front panel meters provide selectable monitoring of output power or VSWR and current, voltage, or ALC.
LED indicators monitor drive levels and XMIT, indicate antenna match, and show she selected antenna. A central display indicates the frequency in use and produces coded messages in case of trouble,
:*he amplifier is designed for a t kW output and typical readings of the output show that the 2000F easily reaches this specification.
Although the 2000F is equipped with a "highspeed arrestor' for protection against lightning surge pulses, I would not trust this expensive device to the whims of nature by retying upon anything less than complete disconnect during storms.
The JRL-200QFs manual is ralher stark when compared 1o the volumes of paper typically accompanying a modem piece of HF equipment. It is, just the same, very adequate. After all. the 20Q0F does nearly everything for you automatically.
Once 1 understood the initial connections and settings. 1 only found it necessary to refer back to the manual to decode aiarm messages when they appeared on the LCD readout (very infrequent and always, in my case, indicative of an operator error).
Maintenance instructions for cleaning the air filters and a troubleshooting chart are part of the manual.
A publication describing JRC's design theory and operation of the 200GF is also provided. It is straightforward, easy to understand, and is not couched in technical language.
Japan Radio Company describes the 2000F as using 48 MOSFETS in the PA section, which consists of four wideband 250W power amplifiers (each has 12 MOSFETS). The PA circuits are SEPP (single ended push-pull) design, providing greater efficiency than standard bipofar transistor/transformer coupled push-pull circuits. The design of the PA focuses on ease of impedance matching for input/output and linearity.
Bias control for the MOSFET SEPP design in class AB operation requires a high gate voltage and high drain idle current. This results in iow high-order fMD and a non-critical bias voltage setting. The bias of the 2000F is controlled partially by the excitation voEtage to achieve extreme stability.
The cooling system for the MOSFET amplifier ■s based upon heat-resistant MOSFETS and temperature actuated fans. The fans are rear facing and generally quiet.
The antenna tuner Is microprocessor-controlled and consists of coils, capacitors, and relays (30 on the luner board). Operation consists of sampling ihe output frequency of the exciter and checking for previous operation on the same frequency.
The 2000F has a memory matrix consisting of a possible four antennas and 455 HF subbands (70 of -vhjch are indicated as within the ham bands in the manual). What this means is that each band is split into smalf segments.
When operating in a particular band segment the unit will search its memory for information matching the frequency. If the unit recognizes the
Was this article helpful?