Posts by iw5bsf

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

yes I confirm that I have noticed the distortion of the transponder

73 de iw5bsf Roberto

Hello

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

Quote from SV1BDS

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

Quote from SV1BDS

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

here is the photo of my tx 2.4 and rx 739/436 mhz transverter

Roberto iw5bsf

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?

Thanks

Roberto

Quote from SV1BDS

iw5bsf if you try it tell me the results.

Hi ok George, I'm looking for the components

73 Roberto

Quote from SV1BDS

The IRF4905 circuit must be OK if you use a heatsink for it and a 7808 or similar solution for 8V.

thank George

73 de Roberto

Quote from SV1BDS

iw5bsf what is the total current of all these stages?

ok 3.5 Amper

Quote from SV1BDS

Hi,

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

thank George

73 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

Hi interesting George, a question that I have to check with my tx's ptt if the 144MHz tx transverter then in sequence the 500 milliwatts to drive the amplifier andrews and what voltage should be sent in tx 28v or polarization bias irq?

73 de Roberto

Quote from SV1BDS

Hi, anyone try this ADF4351 frequency generator?

Hi George, I bought one two months ago, I measured the power of about 0 dm and since it uses the reference 25 mhz tcxo, I try it again and then I send you the photos (used to test my 2.4 ghz pa)

73 Roberto

hello China delete proposal allocation amateurs radio

report link arrl

http://www.arrl.org/news/china…rrent-amateur-allocations

73 de Roberto

Pipe cap 3 cm

I'm glad you solved it! 2.5 db good

Roberto

Quote from SV1BDS

Hi, a 15 mm pipe cap filter for 10 Ghz using guidelines from W1GHZ .

Insertion loss is about 4 dB. Probe lengths are about 3 mm.

BW must be about 200 MHz.

hi George , looking on the internet 2012 RA3WDK pipe filter 3cm loss 2.5 db

73 Roberto

Hi George, thanks for the previous technical support, I wish you new year's eve, I found this interesting link of f6bva converter 10 GHz up converter 2.4 GHz

https://f6bva.pagesperso-orang…e/Satellite/Satellite.htm

73 de Roberto