Posts by PE1RTC

Thanks DC2TH! Unfortunately i have the fake one from aliexpress......

I was already looking in my junkbox for an enclosure and some sma connectors but now i have to find another solution.

I have ordered a lime sdr mini to replace my tx: icom 7300/ ukrain 144MHz transverter/ dx-patrol up-converter.

My plan is to use the lime-sdr mini inside the shack and with 25 meters RG214 the signal goes to a watertight box near the dish with a chinese driver and homebuilt amplifier kit from DK2DB.

I will have 12 dB loss in the coax and i need 20 dBm at the input of the watertight box.

The lime sdr mini will maybe deliver 5 dBm, so i need a total of approx 27 dB gain.

I was thinking about 2x the Opa design F10PA amplifier. One near the Lime and one inside the watertight box but that is an expensive experiment as one F10PA wil cost 49 euro.

Any suggestions for a cheaper solution PA without the MHL21336 or 2x the F10PA ?

73's Gert PE1RTC

Well....i hear some stations with bad modulation. For them it's maybe better to work in FT8 mode....

Without joking, i agree with DV2VH, there's no need for FT8 mode but maybe some stations like to experiment with it.

And if so, please do!

And if you like to take a portable set with you on holiday, FT8 is a quiet solution, so you don't disturb your wife having a glas of wine and reading a book.....

73's Gert PE1RTC

Hello Pete, I would consider to buy a cheap "chinese power meter" with some attenuators and/or a directional coupler.

If you have a small dummyload that coupler is not necessary but is maybe very practical for future in-line measurements.

See other topic "chinese power meter".

I bought one and (if calibrated for 1 frequency like 2400 MHz) it is a very useful meter. As i see that you don't have possibilities to calibrate it you can still use it with for example a 50 dB sma attenuator in series.

In that case you cannot tell the exact amount of power but at least you can see if power goes out!

I saw the meter for 40 euro at Passion radio in France so no need to wait till the Corona virus in China is gone.

I am using this power meter in combination with a chinese directional coupler. At my work i have the possibility to compare it with (calibrated) network analysers, RF power meter and signal generators.

In my case I found that this little power meter is accurate if you calibrate it for one frequency.

Using it on another ham radio band will give complete different and false results.

No problem, if you want to use it for just 2400 MHz, but of course you have to calibrate it for that frequency.

With a 40 dB directional coupler and a 10 dB attenuator added my correction factor is 47,2 to measure 10 dBm power and 47,4 for 37 dBm.

When sweeping the RF generator at qrl from 10 dBm to 37 dBm with 1 dB steps and comparing it to a calibrated HP powermeter i saw no more than 0,5 dB error...so in my opinion it is a cheap and (for ham use) very accurate possibility to do measurements at 2,4 GHz.

For some weeks i used the MK2 with 28MHz, but when i had another look on it with a good hf generator and spectrum analyzer i saw the 2400MHz -28MHz carrier was about 25dB down and the +28MHz carrier only a 10 dB!!

Since that time i use a Ukrain 144MHz transverter between my ICOM 7300 and the DX Patrol MK2.