What do I need to order?
Although the Lunar-Link Systems price list may seem a bit complicated, most of the options are to allow customers to tailor their LA-Series amplifier to their individual stations.
Most of Lunar-Link Systems customers would order an amplifier package which includes everything that is needed :
Amplifier RF deck: LA-72A, LA-12A or LA-22A
RF Power Meter: (Option -060 Adds a Peak Reading RF Power Meter )
Electron Tubes: (2) E-3CX800A7, Eimac Pulse Rated Tubes
RF Relays: P/N 100313, CX-800Ns relay package with cables
HV Power Supply: PS-72
Black Powder Coat Wrap Around Top Cover
That's it, no options required!
Ordering Questions:
Do I need a blower option?
For most customers the standard blower is more than adequate. The standard blower is also very quiet and low in vibration. With larger blowers the noise and vibration increases faster than the cooling capability does. The standard blower is adequate for most customers including those using digital modes such as JT-65 and PSK-443.
The optional high capacity blower, (option -006) may be required if the LA-Series amplifiers are used as follows:
High Elevation (>5000' ASL)
Continuous duty key down for long periods.
50Hz operation with the LA-72, due to the lower plate efficiency at 432 MHz
Option -006 Replace standard blower with 234 VAC blower rated at 100 CFM at 60Hz, 80 CFM at 50 Hz. . This is a high capacity 220/240 VAC.
Why are the RF relays optional?
The RF relays are optional on RF decks to give the customer the flexibility to do what fits their station best. Many operators use 2 feed lines and don't switch the amplifier in and out. Others have found excellent military surplus relays at flea markets or from surplus dealers at bargain prices. By having the relays separate it gives you great flexibility. Amplifier packages come standard with Coaxial Relays.
Do I have to wire in the relays?
The P/N 100313 and 100315 relay packages are all plug and play. Installation requires plugging in the relay power connector (pre-wired) and connecting cables with pre-installed N connectors.
What is the cable and connector kit for?
The P/N 100380 Cable & Connector Kit is intended for customers who will be using their own HV DC power supply. It includes a 6 Pin Cinch female cable connector (S-306-CCT), a MHV male connector for RG-59/U (UG-932/U), 7' of 7 conductor (18 awg) jacketed power cable and 7' of RG-59/U cable for the HV. It is not needed by customers using a Lunar-Link PS-70 series power supply.
What about Svetlana Tubes?
It appears that Svetlana has discontinued the manufacture of the 3CX800A7 / 3CPX800A7 tubes (along with the 8874, 8877 etc.) It has become difficult to receive any firm information about these tubes from Svetlana.
.
I've heard that there are Chinese manufacture 3CX800A7 tubes available and they are very low cost, why doesn't Lunar-Link sell them?
Initial indications are that these tubes are not suitable for use in VHF and UHF amplifiers and that their output power deteriorates very rapidly at 144 MHz and above.
I've got a good source of Eimac 3CX800A7 pulls can I use them?
No problem, that's why Lunar-Link Systems sells the tubes separately. Just remember that tube condition is critical at VHF and especially at UHF (LA-72). So make sure you can return them unless they are at a really, really low price.
Can I use my own HV power supply?
Absolutely! Again flexibility is what the LA-Series is all about. Just remember that you will need about 2300 to 2700 VDC (under load) at 1.1 amperes for the LA-22A and LA-12A and 1.2 to 1.4 amperes for the LA-72A. Remember that the required power supply current is for cathode current (Plate + Grid). Regulation should be as good as practical and ripple should be under 3%. Capacitor input is recommended, choke current is discouraged.
The B- needs to be isolated from ground by a 500 ohm resistor to make the metering and grid over current protection circuits work properly. Finally, a 50 ohm, 100 watt resistor should be in series with the B+ (after the filter capacitors) to prevent damage in case of arcs.
What is the difference between the PS-70, PS-70A, PS-70B, PS-70H, PS-70C & PS-70D?
The PS-70D is the current power supply offered by Lunar-Link Systems for the LA-x2 Series of 1500 watt output amplifiers. It may be used with any Lunar-Link RF deck including the original LA-70B, LA-135 and LA-200.
It has 3 transformer secondary taps allowing the user to run 2300 VDC (full load) with 3CX800A7's or
2700 VDC with 3CPX800A7's. In addition a 2500 VDC output tap is available. The PS-70D's power transformer also has 3 primary taps, 230, 240 & 250 VAC to allow for local variations in line voltage. The PS-70D uses a newer design higher rated 2.5 KV power transformer that uses square primary wire for reduced resistance and voltage drop. The PS-70D uses circuit breakers in the AC mains. The circuit breakers were found to have lower voltage drop and more reliable trip characteristics than the ceramic fuses used in earlier power supplies.
The PS-70D replaces the PS-70C, PS-70, PS-70A, PS-70C and PS-70H. In addition, the PS-70D has the step start circuit protection fuse front panel mounted instead of inside the cabinet.
The following discontinued PS-70 power supplies are compatible with all Lunar-Link amplifiers. The PS-70 was the original Lunar-Link power supply. It had a full load output of about 2250 VDC @ 1.3 amperes. The PS-70A had slightly higher DC output voltage (nominally 2300 VDC at 1.3A) and 3 primary taps to allow adjustment to local line voltage (mains) conditions. The PS-70A incorporated different style power relays than the PS-70. . The PS-70H added 2 secondary taps (3 total output voltages) that in combination with the 3 primary taps allow the operator to select almost any HV output voltage (under load) from 2300 VDC to 2700 VDC. This is applicable to operators who have lower drive, varying line voltage conditions (i.e. home shack verses portable contest location). The PS-70C had the same cabilities of the PS-70H but at a lower cost. Late manufacture PS-70C power supplies have circuit breakers instead of fuses.
Why isn't there a 120 / 240 VAC option on the PS-70D
To run 1500 watts output from a 120 VAC line source (mains) requires over 30 amperes of line current. Few homes have 30 A / 120V circuits. In addition, line voltage sag will make the HV regulation very poor, typically the HV voltage drop under load due to AC power line sag will be 4 times worse that when using 240 VAC. . In general, a 20 Ampere / 120 VAC circuit will allow about 1000 watts maximum RF output, well below the capability of the LA-Series amplifiers. Using a 120 / 240 VAC split primary would also require doing without the 3 primary taps (230 - 240 - 250 VAC) used for HV adjustment.
How about option -004, 220-230-240 VAC / 50 Hz?
This option is for international customers with 50 Hz AC mains. Although there is no harm in running an option -004 power supply from 60 Hz power this option is not needed by U.S. and Canadian customers.
What is the PS-70DX?
What about the PS-70L?
This is a special power supply built primarily for 1296 MHz operators who are using amplifiers running multiple 7289 (3CX100A5) family tubes. The PS-70L runs 1100 - 1250 - 1400 VDC at 2 amperes. The PS-70L is not intended for use with the LA-Series amplifiers.
Lunar-Link Amplifiers © 2002
Web design by K1FO, HTML by K2AH ® 2002