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5

A word about power levels 

 
Your JT-11 is custom designed specifically for the Jupiter transceiver and its power levels. When 
used with the Jupiter, the RF power will automatically be lowered to approximately 20 watts 
during the tuning cycle. 
 
LDG does not recommend using the JT-11 in any other application. If you choose to do so, never 
exceed 125 watts peak power input to the tuner. A minimum of 0.1 watts is required to activate 
the tuner. 
 

Required Tools: 

 
You will need a few basic electronic assembly tools to install your JT-11: 
 
Small soldering iron, 25-40 watts (a temperature-controlled iron is preferred) 
Rosin-core or other solder intended for electronic assembly (NEVER use acid core solder for 
electronic assembly) 
“Solder Wick” solder removal material, or “solder sucker” solder removal tool 
Medium Phillips screwdriver, small hex or star driver 
Small pliers 
Small wire cutters 
 

A few words about soldering and unsoldering: 

 
In one step, you will be instructed to “tack solder” a wire. This refers to soldering a wire end to a 
pad on the PC board where there is no available hole. Simply hold the wire against the pad, heat 
with your soldering iron, and apply a small amount of solder. Hold the wire in place until the 
solder cools. It will help to tin the wire first, flowing solder onto the wire before soldering it into 
place. 
 
In installing your JT-11, you will unsolder two coaxial cable connections on your Jupiter; you 
must remove the excess solder from these connections. You have two options: Solder Wick or a 
“Solder Sucker” solder removal tool. Solder Wick is a metal braid impregnated with rosin. Place 
the end of the Solder Wick against the connection to be unsoldered and heat the wick with your 
soldering iron; the wick will conduct the heat to the solder connection. As the solder melts, the 
wick will absorb it; cut off and discard the used end of the wick and continue until all excess 
solder is removed. 
 
A “Solder Sucker” is a spring-loaded vacuum syringe with a heat-resistant tip. Cock the spring 
plunger, and press the tip against the connection along with your soldering iron. When the solder 
melts, trigger the Solder Sucker; the spring-loaded syringe will pop up, drawing the molten solder 
into the tip. Do this with care, as the jolt of the spring could dislodge your soldering iron. Practice 
a few times with a cold iron to get the feel of it. 
 

Summary of Contents for JT-11

Page 1: ...n Tec Jupiter Manual Version 1 0 LDG Electronics 1445 Parran Road PO Box 48 St Leonard MD 20685 2903 USA Phone 410 586 2177 Fax 410 586 8475 ldg ldgelectronics com www ldgelectronics com Copyright LDG Electronics 2005 All rights reserved ...

Page 2: ...Overview 4 Installation 6 Operation 10 Theory Of Operation 11 Some Basic Ideas About Impedance 11 Transmitters Transmission Lines Antennas and Impedance 11 The LDG JT 11 12 A Word About Tuning Etiquette 14 Care and Maintenance 14 Technical Support 14 Warranty and Service 14 Firmware Upgrades 15 Feedback 15 ...

Page 3: ...eous frequency or band changing Automatic reset of last tuned setting on power up Tuning time 0 1 to 4 seconds full tune 0 1 second memory tune Frequency coverage 1 8 to 30 0 MHz Tunes 6 to 1000 ohm loads 32 to 4000 ohms with optional external 4 1 Balun LDG RBA 4 1 For Dipoles Verticals Vs Beams or and Coax Fed Antenna Optional external Balun allows tuning of random length long wire or ladder line...

Page 4: ...ting coaxial connections and make three new solder connections These are simple steps well within the abilities of anyone with basic electronic assembly skills Simply follow the step by step directions referring to the accompanying illustrations Work patiently read through each step completely before proceeding and check your work often Your workplace should be uncluttered well lighted and well ve...

Page 5: ...hole Simply hold the wire against the pad heat with your soldering iron and apply a small amount of solder Hold the wire in place until the solder cools It will help to tin the wire first flowing solder onto the wire before soldering it into place In installing your JT 11 you will unsolder two coaxial cable connections on your Jupiter you must remove the excess solder from these connections You ha...

Page 6: ...connecting it to the radio via the four cables attached to the tuner one black white pair Control one red wire 12 vdc and two coaxial cables RF IN and RF OUT Step 1 Locate the connection header on the left side of the DSP LOGIC board viewed from the front Locate the two empty pins on this header they are nearest the front of the radio Route the black white wire pair through the notch in the back e...

Page 7: ...just to the left of the RF deck Locate the top center solder pad that already has one red wire soldered to it Carefully tack solder the red wire from the JT 11 to this same solder pad When you re done there should be two red wires soldered to this pad Step 5 Locate the FILTER board It is the vertically mounted board behind the DSP LOGIC board between it and the RF deck You will loosen but not remo...

Page 8: ...om the JT 11 to the FILTER board The RF IN coaxial cable is the one connected to the front of the JT 11 that is the side nearest the front of the radio through a small toroid inductor Connect the other end of this coaxial cable to the FILTER board exactly where you removed the cable in Step 7 The center conductor goes through the toroid Again take care not to damage the toroid on the FILTER board ...

Page 9: ...cover Congratulations You have completed installation of your JT 11 automatic tuner Proceed to Operation Upgrading other Internal Tuners If your radio already has an internal autotuner in it you may be able to upgrade or replace it If it is an LDG tuner V3 5 you can simply purchase a new processor to get the upgraded features see our web site for purchasing information If you have an LDG tuner wit...

Page 10: ...y again your JT 11 will restore these parameters almost instantly much faster than a full tuning cycle Your JT 11 literally learns as you use it You can if you wish force the tuner to run a full tuning cycle even when there are tuner parameters stored for that operating frequency Press the Tune button to start a tune cycle then press it again to abort the cycle Press Tune a third time to clear the...

Page 11: ...hibit resistance and impedance in the form of capacitive or inductive reactance Transmitters Transmission Lines Antennas and Impedance The output circuit of your transmitter the transmission line and the antenna all have a characteristic impedance For reasons too complicated to go into here the standard impedance is about 50 ohms resistive with zero capacitive and inductive components When all thr...

Page 12: ...sipated in the tuner as heat never reaching the antenna at all A tuner simply fools your transmitter into behaving as though the antenna were resonant avoiding any damage that might otherwise be caused by high reflected power Your antenna should always be as close to resonance as practical where F Forward power watts R Reflected power watts SWR Lookup Table Find SWR at intersection of forward powe...

Page 13: ...ate the FORWARD and REVERSE power levels Once adjusted the forward and reverse power sensors produce a calibrated DC voltage proportional to the forward and reverse RF power levels These two voltages are read by the ADCs in the microprocessor Once in a digital format they are used to calculate SWR in real time The relays operate from DC supplied by the power input jack The total current drawn by t...

Page 14: ...hone technical support is available at 410 586 2177 weekdays from 9 am to 5pm Eastern Time Inquiries by Fax at 410 586 8475 are welcome and prompt e mail support is available at ldg ldgelectronics com Warranty and Service Your JT 11 is warranted against defects in parts or workmanship for two years from purchase The warranty does not cover damage due to abuse or exceeding specifications This warra...

Page 15: ...ill be announced on our web site when available Feedback If you have an idea to improve our software or hardware please send us a description If we incorporate your idea in the JT 11 we ll send you a free upgrade as a thank you We encourage everyone who uses the JT 11 to contact us card letter or e mail preferred telling us how well it works for you We are also always looking for photographs of ou...

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