{"id":3570,"date":"2021-04-16T10:57:23","date_gmt":"2021-04-16T08:57:23","guid":{"rendered":"https:\/\/wijnants.info\/fmdx\/?p=3570"},"modified":"2021-04-23T07:44:48","modified_gmt":"2021-04-23T05:44:48","slug":"april-16-2021-lna-and-dab","status":"publish","type":"post","link":"https:\/\/wijnants.info\/fmdx\/april-16-2021-lna-and-dab\/","title":{"rendered":"April 16 2021 – LNA and DAB"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

The other day I bought a Low Noise Amplifier from Amazon UK.
The device is designed by RTL-SDR.com<\/a>.
Inspired by Nils Schiffhauer’s review of Qirx 3.1.2 Beta<\/a> (part 1<\/a> and part 2<\/a>) it was time to check out the RTL-SDR + LNA + Qirx 3.1.2 Beta combo.
Data was always gathered in the same time span and with the same antennas<\/a>.

Reception conditions were flat during these observations, no lift at all.
‘Without LNA’ doesn’t mean switched off but physically disconnected.<\/p>\n\n\n\n

With nesdrSMArtee<\/a> the same results are obtained. However the BIAS TEE cannot be switched off when using nesdrSMArtee!<\/p>\n\n\n\n

Click on the pictures below to enlarge them.<\/strong><\/p>\n\n\n\n\"LNA<\/a>\n\n\n\n

Wideband LNA purchased from Amazon<\/a>.<\/p>\n\n\n\n\"LNA<\/a>\n\n\n\n

My set-up: coaxial lead to the Emme Esse stacked antennas<\/a> is about 20 metres in length.<\/p>\n\n\n\n\"SNR<\/a>\n\n\n\n

SNR (db) readings<\/a> in Qirx are virtually equal when using a LNA or not. There’s certainly no deterioration in signal quality when using this LNA.<\/p>\n\n\n\n\"Gain<\/a>\n\n\n\n

With the LNA hooked up to the RTL-SDR Qirx’s AGC does a great job and the Gain (db) drops considerably.
You can switch off the AGC and go for manual Gain settings, but there’s no need to do so: Qirx’s AGC works just fine.<\/p>\n\n\n\n\"QIRX<\/a>\n\n\n\n

The LNA performs very well when considering Strength<\/a> in Qirx. Strength is represented on a scale from 0 to 1.
Nearby strong transmitters at my QTH like Veltem, Li\u00e8ge or Wavre are of the same ‘Strength’ with or without the LNA.
However more distant transmitters showing up in the TII<\/a> are a different matter and spectacular improvements can be seen.<\/p>\n\n\n\n\"Magnitude\"<\/a>\n\n\n\n

Measuring the ‘Magnitude<\/a>‘ also clearly shows the impact of the LNA.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Conclusion<\/strong><\/p>\n\n\n\n

Do you need this LNA next to your RTL-SDR when doing some serious DAB listening?
It all starts with a good rotatable antenna with a clear view and positioned as high as possible and not too long a coax lead. That’s of course almost impossible, so one needs to find a satisfying compromise.
When there’s no lift or ‘conditions’ at my QTH there’s not much of a difference when using a LNA. No muxes are found which could not be heard under normal conditions, although signal strength has definitely and considerably improved.<\/p>\n\n\n\n

What will happen when there’s a great opening like e.g. on December 29 2019<\/a>?
We’ll have to wait and see…

To be continued.<\/p>\n\n\n\n

Update April 17 2021.<\/strong><\/p>\n\n\n\n

A quick indoors test: a laptop with a short whip. QIRX and RTL-SDR with or without LNA.
Without the LNA 4 muxes can be received. With the LNA 5 are captured.
The test was done several times and always the same results were obtained.<\/p>\n\n\n\n\"No<\/a>\n\n\n\n\"LNA<\/a>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

The other day I bought a Low Noise Amplifier from Amazon UK. The device is designed by RTL-SDR.com. Inspired by Nils Schiffhauer’s review of Qirx 3.1.2 Beta (part 1 and part 2) it was time to check out the RTL-SDR + LNA + Qirx 3.1.2 Beta combo. Data was always gathered in the same time… <\/p>\n

Read the full article<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,15,17,18],"tags":[],"class_list":["post-3570","post","type-post","status-publish","format-standard","hentry","category-dab","category-hardware","category-radio","category-software"],"publishpress_future_action":{"enabled":false,"date":"2026-05-10 18:07:54","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/posts\/3570","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/comments?post=3570"}],"version-history":[{"count":0,"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/posts\/3570\/revisions"}],"wp:attachment":[{"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/media?parent=3570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/categories?post=3570"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wijnants.info\/fmdx\/wp-json\/wp\/v2\/tags?post=3570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}