Morris Hughes Technologies Mini LONGWAVE PLL
*LONGWAVE Phase Locked Loop Unit
*Designed on YOUR frequency!
*Filtered Range 50- 255 kHz sinewave
*Unfiltered Range 1-255 khz squarewave
*Super tiny! - 76 by 32 by 15mm - mounts anywhere!
*Designed to mount inside your AM transmitter
*Designed for single frequency use for your AM transmitter
*Can be frequency modulated (NBFM option)
*Many other uses!
Fully built PC board. No SMD! Custom built on YOUR frequency.
This is a PLL, not a DDS. Covers 50 to 255 kHz in 1 kHz steps. Old school CMOS technology
We can custom build yours lower than 50 kHz upon request only.
These long wave PLL units are filtered and are only about 50 kHz wide at 250 kHz and 10 kHz wide at 50 kHz.
The lock range is 50-255 kHz but the useful bandwidths will be less per filter design.
Designed to replace expensive/hard to find crystals for your AM transmitter
Fully filtered output/pure sine wave. Harmonics 30 dB down
Frequency drift is less than 1 Hz at carrier
Power required: 11 to 15 VDC (28 mA typical) Reverse Emf protected
**please consult your transmitter manual for proper interfacing**
Board pictured is our longwave PLL with no filtering installed; connection wires not shown.
FULLY BUILT, TESTED AND ALIGNED ON YOUR REQUESTED FREQUENCY! NOT A KIT!!
Advantages of a PLL vs. a DDS: A PLL can easily be frequency modulated where this is generally impossible with a DDS.
Also, most DDS units have an LCD display with a confusing and frustrating 'one knob' menu navigation. So if all you need is
a single frequency and don't want all the extra menus and features that you will never use, and you want PLUG AND PLAY....
then our MINI PLL is what you need!
Our Mini PLL is capable of working the 50 to 255 kHz range in 1 kHz steps. The upper end is limited by the 8 bit divider's 255
possible states. Contact us for your specific needs! PLEASE UNDERSTAND: This PLL, because of the output filtering, will only
cover your requested frequency, plus or minus about 50 kHz. Unlike our medium wave PLL (in another auction) this output filter
is FIXED (soldered) to the board and is NOT user adjustable. Does not have a filter socket. As such we MUST know what
frequency you desire to custom design your PLL. Upon request we can supply this unit without a filter, but keep in mind the output
will be squarewave and rich in harmonics.
IMPORTANT! WHEN YOU ORDER WE NEED TO KNOW 2 THINGS:
1- Your desired frequency. If you order our PLL with a filter we NEED to know your desired frequency so we can build the
filter. Your requested frequency is a multiple of 1 kHz. Example, 170 or 171 kHz is OK but 170.5 or 171.75 will not work.
2- Filtered or unfiltered? We can build yours to fit your needs.
Custom built:
Also, let us know if you need your PLL to operate below 50khz (with/without filter)- we can custom build this for you. For design
and filter considerations we suggest no lower than 15 or 20 kHz. FM stereo circuit design? No problem- we can do 19 or 38 kHz.
If you require frequencies above 255 kHz please see our other Mini PLL auction covering 250 to 2,550 kHz in 9 or 10 kHz steps.
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WHAT YOU GET:
You will receive one Mini PLL Board on YOUR FREQUENCY along with extensive ENGLISH instructions on mini CD, including
board layouts, schematics, and an all-important PLL divider look-up table should you ever need to change frequencies. We highly
recommend that no filter part changes or other modifications be performed since the PC board is very small and easily damaged
by improper soldering.
WHAT YOU WILL NEED:
The only other thing you need is a super quiet low ripple DC power source. We cannot emphasize enough that the DC be clean
because a noisy power source will surely frequency modulate hum onto your carrier. This noise will set up FM sidebands and
cause interference. For critical phase sensitive applications such as in all AM stereo systems, any percentage of supply hum and
noise is unacceptable. We suggest using a high frequency switching supply (such as the small inexpensive Meanwell 'cage' types.)
The board mounting hole dia is 2.5 mm. We recommend using two 2.5 mm metric screws(diagonal) with appropriate spacers to
mount the board. No mounting hardware included.
We use a three IC CMOS well known, tried and true design. Why spend your valuable time breadboarding and probably
troubleshooting your own PLL when we have what you need right here?
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Circuit Specifications:
VCO Lock Range: 50- 255 KHz in 1 KHz steps. Max frequency is 255 kHz
Max divider range: decimal 1 to 255 (8 bit) programmable divider
Lock time: less than 1 mS
Frequency Tolerance: +/- no more than 1.5 Hz drift from 30-90 degrees F after 30 min warm-up. Approx. -4 to +4 Hz reference
calibration range (at carrier.) Maximum temperature range of VCO: 15 to 110 degrees F. System may unlock outside of this range.
Phase Noise: Better than -40 Db. down depending on power supply.
Operating voltage: 11 to 15 volts. 12.5V optimum. Do not operate unit outside of this range! Reverse voltage protection diode included.
Current draw: 28 mA at 12.5 V
RF output: approx. 10 mW filtered sine wave high 1 K ohm impedance. Varies depending on filter curve.
DC block: 100V isolation capacitor included at RF output for safe interfacing.
VCO absolute maximum design freq: 3 Mhz.
IC compliment: Three CMOS 4000 family
IC sockets: Three included, 16 pin DIP
Board dimensions: 1.25 inches W by 3 inches L by 0.57 inches H. (32 by 76 by 14.5 mm)
Board mounting hole dia: 2.5 mm (distance between holes, 71 and 26.5 mm)
Three wire interfacing: Blk- gnd, Red +DC, Blu- RF out (Yellow wire- optional NBFM audio IN)
External optional narrow band FM (NBFM) input per instructions
We are a new company to Ebay and would really appreciate positive feedback. We have built over 100 of these circuits and
have not had a single failure in over 10 years. Reliability and frequency tolerance is exceptional and each unit is cleaned and
tested before shipping. We stand by our products 100% and guarantee performance. In the highly unlikely event of a failure or
if you are not satisfied about something, please contact us first and we'll make it right. Contact us if you have any operational
questions or application questions, or need help on a specific problem.
MHT Mini PLL Unit with instructions, layouts and schematic on CD
Just $ 45 with FREE SHIPPING.
We will ship overseas using US Mail postal rates.
Proudly assembled in the USA. God Bless AMERICA!