EME231 SP5055 Wideband PLL

EME231 Description:

The EME231 PLL Kit is a 4 Channel PLL that is suitable for wide bandwidth modes including FM Television, and is generally not suitable for narrow band modes like SSB due to the high phase noise of the SP5055 PLL chip. The PLL Kit has been primarily designed to be used in conjunction with the EME153 ( 2.4GHz ), and EME154 ( 1.2GHz ) 2400 and 1250MHz video transmitter kits, and is only suitable for wide bandwidth modulation modes like FM ATV or Data. The frequencies can be easily programmed into the on board PIC micro controller using a low cost PIC programmer like the PICKIT 2 or 3. No LCD display module or external frequency tuning control is required. The EME161B Controller can be added to control the PLL which then allows an LCD display module to be used to shows a display multiplier when a 1.2GHz transmitter is used on the higher microwave bands. Bands can then also be selected by using a band switch on the EME231 PLL board and frequencies can then also be memorized for the different bands.

Kit Constructors Alert:

1/ There are no alerts or issues with this Kit.

EME231 Construction Notes:

The construction is quite straight forward and many of the components are easily fitted with tweezers. The Kit construction notes and overlay diagrams should be carefully followed when constructing. For larger pictures to check orientation of some components click the images below. Remember to fit the wire link to the deviation trim pot under the board. BUY THIS PRODUCT

  • EME231 Top View
    The picture shows a completed EME231 Rev1.0 board. There is a minor change to the revised Rev1.1 board to move a capacitor to the bottom side of the board and fix a small mistake with a track
  • EME231 PCB Bottom View
    This picture shows the bottom side of the Rev1.0 board


The EME231 PLL Kit is supplied with a PIC12F629 micro-controller pre-programmed with either PLL_TX12 software to suit 1150 to 1300MHz, or PLL_TX24 to suit 2300 to 2500MHz.. The software allows up to 4 pre-programmed channels to be selected. Please refer to the PLL_TX12 Software documentation for further information. When using the EME161B controller with the EME231 PLL, the PIC12F629 is removed from the board as it is not required.

Even though the software has the provision to use a one button programming function to set frequencies, It is recommended that the frequencies are programmed into the PIC 12F629 using a PIC programmer as there are some bugs in the software that can lockup the micro controller indefinitely.

When the frequency is changed, it is assumed that the PLL is unlocked. The PIC checks the PLL status continuously until the PLL locks. Once locked, status checks are made every
second. if the PLL goes out of lock, continuous checks are started again. (to disable the checks every second, change the 'LOCK_TM' equate to 255)

Changes and Updates:

1/There are no changes to this Kit