Welcome to my Web site!                                     M.A.Pinfold     ZL1BTB      mapinfold@yahoo.com

1.       Dunedin Linear Repeater                                       

2.      Rotorua Linear Repeater 

2a     The Rotorua linear Repeater  MK 2 rebuild               

3.      Coaxial Resonators

4.      Codan HF SSB Repeater Project


5.      Contemporaneous  On-Frequency   Repeater (not the Plessey patent)

      The Plessey Avionics PTR3411    Contemporaneous FM repeater!!

 7      Common Channel communications 

8       Direct Conversion FM  Receivers. 

8.      Circulators   (under construction )

9       Long Range  Bluetooth  Data Transfer 

10     Jamming Enforcement Doppler radar         a few thoughts! 

11     Reciprocating detector For SSB /DSB/ CW

12     Second generation reciprocating detector

13    The Synchronous   Oscillator 

13A   Frequency Demodulation  assisted by Synchronous oscillator

14     Common Rail Diesel injector interference     Isuzu  bighorn               updated nov 2013

15     Superregenerative detector operating at  H.F 

16     Half Wave Dipole Resonants Lengths @ H,F

17      A Remote Controlled HF  Communications  Receiver via  DTMF  ,    ICom     IC-R75.  

18      A  motorcycle mounted 2m  dipole antenna

19      Digital Radio Mondiale convertor 455 to 12 Khz

20      Double Sideband suppressed carrier demodulation  ,  MC1496 as squaring means

21      DSSC    demodulation by the squaring means     diode doubler technique  

22   simple narrow filters  

23     Double sideband demodulator  mk3  squaring loop

24     NE567 Tone Decoder as AM FM   demodulator at 455 KHz

25     29 MHz  Coaxial resonator  for the 10m Band

26     Quartz crystals       Where to purchase inexpensive

27     Mini Circuits   Low Pass filters .... SMD        

28     9:1  un-un for HF  receive only 

29    The SA828 UHF  Transceiver  Module 

30     Measuring second harmonic level via notching the fundamental frequency


32    V/U chinese tracking generator and Spectrum analyser  

33    Chinese preamps off the web

34    29 MHz J Pole       

35    Super regenerative receivers , quench investigation  

36    Amplitude modulation of 2.5 GHz WBFM systems   

Tuning a ferrite Circulator

38.    H.F Antenna for  RV  Vehicle

39.    R.F splitters  and combiners (3dB)  for H.F.


This page was last updated on 20-10-2022.



Repeater Links try:      http://www.repeater-builder.com  

RF  test equipment links      http://www.rftest.co.nz/     

 Digital radio solutions             http://www.4rf.com                                     

        click below

Check out my other site that pays the bills to enable this site to exist!          2.4 GHz video cameras video senders, receivers , 802.11b Wireless Lans, Motorcycle intercom radios, 2.4 GHz antennas bone conduction mics, Vox units  etc.......all in $NZ  (much less than $US!!)