LNA4HF Now for Sale Plus Review
Back in November last year we posted about the possibility of an “LNA4HF” low noise amplifier (LNA) for the HF bands being made available for sale. The LNA4HF is now available for purchase.
The LNA4HF is a low noise amplifier with built in low pass filter that runs on a 6-12 V power supply and covers a frequency range of 150khz to 30MHz, with a 18-20 dB gain and 1-2 dB noise figure. It costs 20 Euros. The low pass filter can also be disabled with a small board modification which will allow the amplifier to be useful at up to 2 GHz.
Akos from the SDR for Mariners blog has reviewed the LNA4HF on his latest post. His results show that the low pass filter significantly reduces broadcast FM interference and that the amplifier also increases signal strength by around 20 dB as advertised.
I might have missed it but I have yet to find a link for placing an order and purchasing the LNA4HF. Do I just need to contact the builder directly via email to place an order or is there an online source available?
Yepp, go to the product webpage and send an email.
I included his contact details in my review, see at:
The external environment noise figure is totally stronger than the noise figure of your system on HF band …..
I understand his beef now. His complaint is that it is advertised as an ‘LNA’ at HF frequencies, where the natural background noise makes a 2dB NF meaningless. He apparently missed the part of the story where this amplifier is easily altered for use up thru 2Ghz. The only thing that makes this an HF band amp is the lowpass filter, otherwise it is the same as an LNA4ALL.
He isnt upset about it being used as a preamplifier at HF, he is upset about it being called an LNA at HF.
But it’s true than on VHF or UHF it could useful as LNA …. 73 !
Got my LNA4HF last week from Adam. Its a HUUGE improvement!
Many thanks for the article, an interesting read.
As Ive written the review on it I strongly recommend to try a preamp before commenting on its usefulness, having a preamp is a whole new level of experience. Bottom line is: you hear more signals, more fun.
Why is it useful to have a LNA between150 Khz – 30 Mhz ????? ……. totally unuseful …….
Because the SDR dongle itself is one of the largest sources of noise at those frequencies, limiting the usefulness of its own internal gain setting. Having an LNA at the antenna allows boosting of the signal before it gets to the dongle’s noisy environment.
I fail to see the relevance of the article you site, as it pertains with the amplification of a received signal.