Posts by iw5bsf

    I took a look after reading your directions datasheet 4351 page 22 it says register 3 also serves to determine TIMER AND FAST LOCK REGISTER SEQUENCES TER

    Thanks for the answer, I use the pickt3 as a programmer following some indications on the net I put a resistor between VDD and MCLR for programming

    the sequences in the asm file up to these:


    DE 0x00, 0x7D, 0x80, 0x10 ; register R0 2514,000Mhz // ok

    DE 0x08, 0x00, 0x80, 0x29 ; register R1

    DE 0x00, 0x00, 0x4E, 0x42 ; register R2

    DE 0x00, 0x00, 0x04, 0xB3 ; register R3

    DE 0x00, 0x85, 0x00, 0x3C ; register R4

    DE 0x00, 0x58, 0x00, 0x05 ; register R5

    therefore the sequences must be reversed

    hello help pll ADF4351 PIC12F675

    i made the converter 433 mhz / 10489 for qo-100 as LO I use pll ad4351 with controller pic12f675 i as a reference I use external 10 mhz of the isotemp 131-100 it is very good problem that if I turn on the pll the lock does not turn on if I turn off then I turn on first the external reference 10mhz and then I turn on the pll so does any idea work?

    i used this project;


    73 de iw5bsf Roberto

    hello George

    looking on the internet I found this nxp module could it work at 2.4ghz? I attach date shhet it seems to me twin mhl21336

    73 de iw5bsf Roberto


    • MHPA21010.pdf

      (147.92 kB, downloaded 240 times, last: )


    I made the IF0 RT0 10 GHz a few years ago (designed by s53mv) I modified the original 27 MHz vxo oscillator to receive QO-100 the tested with excellent results it seems NF is around 0.7 db beacon 10489

    I listen to the beacon very well the stability of the quartz very good unfortunately the range and only a few khz I'm waiting for the crystall ordered to cover 500 khz of band

    73 de iw5bsf Roberto

    thank you good idea I do one in the next few days

    i don't have vna but i can measure with hp bolometer and rf generator

    73 Roberto

    Hi Roberto, it seems that you have 21.87 dB coupling and 35.89 dB directivity that are good values. You can verify with AD8302 these values if you put in generator -10dBm. You can measure the ratio for coupling and directivity. Also you can repeat my fault measurement and then put attenuators to fix it. The coupling value means that you have the forward power 20 dB less and the directivity value that you can not measure less SWR than 35 dB i.e. about 1:1.1

    Good morning George yesterday I remeasured the directional coupler 2.4 GHZ the only measures but with one hour of heating of the bolometer hp as the manual says good results 23 db of coupling and the directives 39 db what do you think

    73 de iw5bsf Roberto

    iw5bsf I have done something similar. You are right about the values. The critical is the ground paths of the two 56 ohm resistors. If they have inductance to the ground the actual attenuation will be smaller. To avoid high power passing I replaced variable R with a fixed one. Also use metal film or carbon for all as the usual resistors are inductive. I have also the W1GHZ 2.4 GHz transverter and begin assemby it for simplex usage.

    Thank George, I put 560 hom fixed as indicated by the 5% tolerance of metal oxide that I tried before measuring the measured power ft87 on 27.7 dbm then inserted the attenuator (26.8 db considering the tolerance of the resistors) at the output = 0.90 is ok

    73 de iw5bsf Roberto

    Good morning George, I saw the notification of the message on my e-mail ok good test just yesterday I did some practice on the directional couplers. My good transverter I have to make an attenuator from 500 milliwatt to 1milliwatt in input if tx the pi attenuation calculated 27 db of attenuation two 56 hom resistors and one 560 i resistor but to be able to vary I have to put a 1khom trimmer in replacement 560 h resistor correct?




    A VOX circuit to provide PTT from 1W SSB UHF without power supply.

    Hi George, good idea, my W1GHZ transverter, I only mount the TX part, I drive it with a 500mw power RTX ft817 attenuator to get 0dbm on the IF144 MHZ. In transmission I have to give + 8v to the final stage which produces an output of 35 milliwatt 2.4 ghz followed by a 500 milliwatt amplifier >>>>> and an andrews amplifier appeared on the forum

    With the ptt in tx I have to supply + 8v transverter + 12v 500mw amplifier and +12 PA if you have any suggestions are welcome

    73 iw5bsf Roberto

    Sorry, I explained badly practice the amplifier that I use from 10 watts 2.4 ghz to two voltages that 28v + and that idq + when I go to tx I only have to give voltage to the idq, the 28 volts must always remain fixed even when I'm not going to tx

    73 Roberto