Thanks , Mike for the video on the Mini Whip active Ant. I got one from PA0RDT . It ships very fast. Very well made and mounted on the side of my house like you and its works great,Out preforming my long wire up in the trees 30 feet. Now I just need to clear up some computer noise and other electrical noises as I want to listen to VLF like you. I have the Air spy and the SDRPlay but very fun to listen to . Just love your videos and web page. Thanks
people who report poor performance with the PA0RDT seem to be blissfully unaware that good, real grounding is crucial to the mini-whip. real ground in the ground, not "ground" off a pipe in your house.
Absolutely true! Grounding the outer conductor (shield) of the coaxial cable has to be done properly! Coaxial cable is part of Mini-Whip antenna and collect a lot of RF noise. You can treat Mini-Whip antenna as a vertical antenna feeding at the top where the impedance is very high. Outer conductor of the coaxial cable must be grounded at the bottom of antenna, where the coaxial cable touching the ground, and the second grounding have to be done at the point just before coaxial cable entering in the house. The RF isolating transformer is recommend also. In that way receiver ground is not physically connected to antenna ground but it is galvanic isolated from outer shield of coaxial cable. All this measures are not difficult to implement and cost almost no money, but the benefit is clear, noiseless VLF and HF reception!
@@tglenn3121 ciao esattamente così non vale nulla é semplicemente un amplificatore da 20db , se vuoi farla funzionare meglio devi aggiungere un pezzo di filo lungo tra 1 metro massimo 1,5 metri lo saldi sulla piastrina di rame della mini wip , il filo lo. devi tenere bene teso in verticale , dentro al tubo di plastica che vedi nel video
Have you got a video / tutorial on how to connect and use 10 kHz - 30 MHz active antenna (the Chinese ones on ebay) to laptop and receive LF signals on GNU Radio Companion (Linux)? Thanks.
Hello. Please show how we can listen between 10 khz and 30 Mhz with SDR rtl2832u r820t2 receiver. I made a (mini whip) antenna but I didn't know how to connect it. Thank you.
What is that 1M resistor from the voltage divider at the gate of J310 to the drain??? Remove that, and you will get really good signal. I made different system for VLF with single J310, resistor and capacitor from the source of J310 to ground (I think it was 200 Ohms + 100 nF, but not sure), and drain is connected directly to the center of the coaxial cable. At RX end, there is coil as suppressor to 12V PSU, and 100 nF capacitor to the RX input. At the time, I had no other receiver than just sound card - with some TL071 opamp, got excellent result from 0 Hz up to 24 kHz (depending of sound card sampling rate (it was 48 kHz). VLF broadcast from submarine stations are heard at 25 Hz (!)... and everything else on this range... The "receiver" is just CoolEdit program for visualizing the spectrum and eventually listen audible sounds. Recorded signals can be demodulated by post-processing in the same program.
On July 3rd, 2016 We will have another opportunity to catch the signals from Grimeton on 17.2 KHz... Here is my video from the last year: ua-cam.com/video/lwFxjmcMDiQ/v-deo.html
It depend if you are in rural area away from strong RF signals which can overload frontend of the mini-whip. Take into account that whole coaxial cable (outer shield of the coax) is acting as antenna. Actually mini-whip is vertical antenna formed by coaxial cable shield. The signal from vertical antenna is taken from the top, where the frontend of the mini-whip is. That is why the coaxial cable shield must be grounded at its bottom, where the cable meets ground. The impedance on the top of the vertical is very high, adequate for first FET- transistor input.
Hi Steve, The large antenna will introduce IMD and other non-linear distortion because the amplifier front-end will be overloaded with much stronger input signal then needed!
Hvala Mile na usavršavanju ideje, sprečavanje galvanskog kontakta je svakako dobra stvar da se spreči prenos nepotrebnih signala i ja ću ga primeniti. Da li ste videli ovo unapređenje: enlite.org/miniWhip.jpg Malo sam korigovao shemu u mom slučaju pa sam umesto feta upotrebio mosfet BF998 zbog 0,6 db šuma i cene od samo 10 centi.
Da. Znam ovu shemu. Nisam je testirao. Ipak, kad se radi od frekvencijama do oko 20 MHz, onda je shum irelevantan, jer ionako atmosferski i galakticki shum su daleko veceg nivoa. Na ovim frekvencijama je najvazniji dinamicki opseg pojacavaca, odnosno sposobnost pojacivaca da bude linearan i pri prisustvu veoma jakih signala na ulazu. J-310 je odlican u tome. Pozdrav,
Thanks , Mike for the video on the Mini Whip active Ant. I got one from PA0RDT . It ships very fast. Very well made and mounted on the side of my house like you and its works great,Out preforming my long wire up in the trees 30 feet. Now I just need to clear up some computer noise and other electrical noises as I want to listen to VLF like you. I have the Air spy and the SDRPlay but very fun to listen to .
Just love your videos and web page.
Thanks
Hi Gail, I am glad that you are happy with PA0RDT Mini-Whip. 73
Excellent! Waterpipes. Great hint. I'll give that a try. Cool idea!
it appears that a longer wire attached seems to give intermodulation with AM/FM, so its better to experiment with the shortest bit of wire if any.
people who report poor performance with the PA0RDT seem to be blissfully unaware that good, real grounding is crucial to the mini-whip. real ground in the ground, not "ground" off a pipe in your house.
Absolutely true!
Grounding the outer conductor (shield) of the coaxial cable has to be done properly!
Coaxial cable is part of Mini-Whip antenna and collect a lot of RF noise.
You can treat Mini-Whip antenna as a vertical antenna feeding at the top where the impedance is very high.
Outer conductor of the coaxial cable must be grounded at the bottom of antenna, where the coaxial cable touching the ground, and the second grounding have to be done at the point just before coaxial cable entering in the house.
The RF isolating transformer is recommend also. In that way receiver ground is not physically connected to antenna ground but it is galvanic isolated from outer shield of coaxial cable.
All this measures are not difficult to implement and cost almost no money, but the benefit is clear, noiseless VLF and HF reception!
I have my PAORDT antenna attached to a 'ground' in the ground and the performance still sucks!
@@tglenn3121 ciao esattamente così non vale nulla é semplicemente un amplificatore da 20db , se vuoi farla funzionare meglio devi aggiungere un pezzo di filo lungo tra 1 metro massimo 1,5 metri lo saldi sulla piastrina di rame della mini wip , il filo lo. devi tenere bene teso in verticale , dentro al tubo di plastica che vedi nel video
Have you got a video / tutorial on how to connect and use 10 kHz - 30 MHz active antenna (the Chinese ones on ebay) to laptop and receive LF signals on GNU Radio Companion (Linux)? Thanks.
Hello. Please show how we can listen between 10 khz and 30 Mhz with SDR rtl2832u r820t2 receiver. I made a (mini whip) antenna but I didn't know how to connect it. Thank you.
What is that 1M resistor from the voltage divider at the gate of J310 to the drain??? Remove that, and you will get really good signal. I made different system for VLF with single J310, resistor and capacitor from the source of J310 to ground (I think it was 200 Ohms + 100 nF, but not sure), and drain is connected directly to the center of the coaxial cable. At RX end, there is coil as suppressor to 12V PSU, and 100 nF capacitor to the RX input. At the time, I had no other receiver than just sound card - with some TL071 opamp, got excellent result from 0 Hz up to 24 kHz (depending of sound card sampling rate (it was 48 kHz). VLF broadcast from submarine stations are heard at 25 Hz (!)... and everything else on this range... The "receiver" is just CoolEdit program for visualizing the spectrum and eventually listen audible sounds. Recorded signals can be demodulated by post-processing in the same program.
ua-cam.com/video/fKSOoZ2vhvo/v-deo.html
SAQ day soon, would be good to see how it works receiving SAQ
On July 3rd, 2016 We will have another opportunity to catch the signals from Grimeton on 17.2 KHz...
Here is my video from the last year:
ua-cam.com/video/lwFxjmcMDiQ/v-deo.html
Best reception is a with 1m whip - increases hight
Amazing ! Question: wouldn't adding more metal area help with reception?
73 N8AUM
It depend if you are in rural area away from strong RF signals which can overload frontend of the mini-whip. Take into account that whole coaxial cable (outer shield of the coax) is acting as antenna. Actually mini-whip is vertical antenna formed by coaxial cable shield. The signal from vertical antenna is taken from the top, where the frontend of the mini-whip is. That is why the coaxial cable shield must be grounded at its bottom, where the cable meets ground. The impedance on the top of the vertical is very high, adequate for first FET- transistor input.
Would you get stronger reception with a larger antenna of 3 Meters or more?
Hi Steve, The large antenna will introduce IMD and other non-linear distortion because the amplifier front-end will be overloaded with much stronger input signal then needed!
Without power supply 9 v dc , does parrot antenna works well?
I do not know about the Parrot antenna (did not tested yet) but, my mini whip antennas works great with 15-16 V DC.
Ne rade linkovi ka shemama.
Hvala na informaciju. Zamenio sam linkove i sada bi trebalo da je sve u redu. Pozdrav
Hvala Mile na usavršavanju ideje, sprečavanje galvanskog kontakta je svakako dobra stvar da se spreči prenos nepotrebnih signala i ja ću ga primeniti. Da li ste videli ovo unapređenje:
enlite.org/miniWhip.jpg
Malo sam korigovao shemu u mom slučaju pa sam umesto feta upotrebio mosfet BF998 zbog 0,6 db šuma i cene od samo 10 centi.
Da. Znam ovu shemu. Nisam je testirao. Ipak, kad se radi od frekvencijama do oko 20 MHz, onda je shum irelevantan, jer ionako atmosferski i galakticki shum su daleko veceg nivoa. Na ovim frekvencijama je najvazniji dinamicki opseg pojacavaca, odnosno sposobnost pojacivaca da bude linearan i pri prisustvu veoma jakih signala na ulazu. J-310 je odlican u tome. Pozdrav,