{"id":41879,"date":"2020-02-06T10:08:38","date_gmt":"2020-02-06T14:08:38","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=41879"},"modified":"2020-02-06T10:08:38","modified_gmt":"2020-02-06T14:08:38","slug":"guest-post-radiofreunde-nrws-dxpedition-grade-signal-distribution-system","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2020\/02\/guest-post-radiofreunde-nrws-dxpedition-grade-signal-distribution-system\/","title":{"rendered":"Guest Post: Radiofreunde NRW&#8217;s DXpedition-grade signal distribution system"},"content":{"rendered":"<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-40821\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1-1024x768.jpg\" alt=\"\" width=\"625\" height=\"469\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1-1024x768.jpg 1024w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1-300x225.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1-768x576.jpg 768w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1-1536x1152.jpg 1536w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1-624x468.jpg 624w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-1.jpg 1984w\" sizes=\"auto, (max-width: 625px) 100vw, 625px\" \/><\/a><br \/>\n<em><strong>Many thanks to SWLing Post contributor, Joachim von Geisau (DH4JG), for the following guest post:<\/strong><\/em><\/p>\n<hr \/>\n<h1>Signal distribution at SWL camps: The new JK-1000 HF distributor<\/h1>\n<p style=\"text-align: right;\"><strong>by Joachim von Geisau (DH4JG)<\/strong><\/p>\n<p>The <a href=\"https:\/\/swling.com\/blog\/2019\/11\/photos-from-the-radiofreunde-nrw-dxpedition\/\">Friends of Radio NRW<\/a> &#8211; an independent group of shortwave listeners and radio amateurs in Germany &#8211; have been organizing 2-3 SWL camps per year for a number of years, where they meet as far away as possible from electrical noise in order to listen to shortwave together.<\/p>\n<p>To distribute antenna signals, we have previously used an RFT AVV01 antenna distributor.<\/p>\n<p>At an SWL camp there are high demands on signal distribution. Both very weak and strong signals should be distributed well, un-distorted, without noise and other interference. The signal levels are approximately between 0.2 ?V (S1) to over 5 mV (S9 + 40 dB), with a frequency range of at least from 150 kHz to 30 MHz, thus broadcast bands from LW to SW are covered, also all amateur radio bands from 160 m to 10 m.<\/p>\n<p>Popular among listeners are RFT AVV01 RF distributors from the former GDR, at least 30 years old. However, the use of an AVV01 has several disadvantages: high power consumption, difficulties in getting spare parts, high upkeep with corroded contacts and the like. In addition, the transmission of the LW\/MW range drops, which is a disadvantage especially for MW listeners. The NV-14 system from Rohde &amp; Schwarz from the late 1960s has the same weaknesses.<\/p>\n<p>Two years ago, the desire arose to develop a concept for the replacement of the RFT system.<br \/>\nThe following aspects were important:<\/p>\n<ul>\n<li>Frequency range at least 100 kHz &#8211; 30 MHz, as linear as possible<\/li>\n<li>frequencies below or above desirable<\/li>\n<li>Running on 12 V DC or integrated noise-free power supply<\/li>\n<li>Remote power supply for active antennas<\/li>\n<li>Robust structure<\/li>\n<li>Versatility<\/li>\n<li>Hobby friendly budget<\/li>\n<\/ul>\n<p>The amateur radio market offers several products for RF signal distribution (e.g., ELAD, Bonito et al.), but no solution to distribute 6-8 antennas to 10-12 receivers. It was clear from the beginning that DIY development was inevitable.<\/p>\n<p>The starting point of the considerations was to integrate remote power supply for active antennas, an amplifier stage and a distribution network.<\/p>\n<p>Such a distributor is able to distribute an antenna signal to several receivers; several antennas require several such distributors, which led to the decision to implement the project in plug-in technology.<\/p>\n<p>With OM Frank Wornast DD3ZE (<a href=\"http:\/\/www.dd3ze.de\" target=\"_blank\" rel=\"noopener noreferrer\">www.dd3ze.de<\/a>), known e.g. for his converters, filters and the like, a well-known RF developer could be won, who took over the implementation of the concept based on the detailed specifications. OM Wornast first produced a prototype without remote power supply, which already did an excellent job of RF signal distribution.<\/p>\n<p>A &#8220;hardness test&#8221; at an SWL camp showed that this distribution module easily fulfilled our requirements: Frequency range 10 kHz &#8211; 50 MHz (also usable with a few dB loss above 50 MHz). Supplemented by a switchable remote power supply and a 90V gas discharger at the antenna socket, the final PCB layout was created, representing the core of the new HF distribution system of Radio Freunde NRW<\/p>\n<p>The distribution block consists of the following components:<\/p>\n<ul>\n<li>Input with 90V arrester &amp; 100 kOhm MOX resistor to dissipate static interference<\/li>\n<li>Remote power supply, switchable, 10-14 V, max. 350 mA<\/li>\n<li>Amplifier stage with 14-14.5 dB<\/li>\n<li>Resistor network for distribution<\/li>\n<\/ul>\n<p>The device is characterized by a very smooth frequency response and has a very low inherent noise. It offers the possibility of using levels of -120dBm with very good SNR<br \/>\nto process up to strong levels of up to + 14dBm. In addition, the reception on VLF is now possible, which did not work with the previous system.<\/p>\n<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel-Internal-e1580996610259.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-41881\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel-Internal-1024x768.jpg\" alt=\"\" width=\"625\" height=\"469\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>The PCB is designed in a very practical way: series resistors for LEDs are integrated as well as fixing points for coaxial cables. The remote power supply can be switched separately, but can also be used permanently by means of a jumper.<\/p>\n<p>With this concept, the distribution block can be used universally: use on an active or passive antenna with distribution to several receivers, by means of a step switch in front of it also for several antennas; if you leave the remote feed path unconnected, the block can also be used as a simple distributor, so it is almost universal for hobby purposes.<\/p>\n<p>For use on SWL camps, we decided to install them in 19 &#8220;rack-mount technology. A standard rack can thus accommodate 4 distributors and a power supply, allowing\u00a0 distribution of 4 antennas to 12 outputs each. An example of the installation is shown in the following picture: Parallel to the input is another BNC socket, which is connected via a C 100 nF where the input signal can be used DC-free for measurement purposes or the like. The distribution unit is installed in a transport case. The components themselves are mounted in slide-in housings which are provided with a corresponding front panel: Such front panels might be obtained from CNC manufacturers.<\/p>\n<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-41880\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel.jpg\" alt=\"\" width=\"990\" height=\"660\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel.jpg 990w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel-300x200.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel-768x512.jpg 768w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/Amplified-Antenna-Distribution-panel-624x416.jpg 624w\" sizes=\"auto, (max-width: 990px) 100vw, 990px\" \/><\/a><\/p>\n<p>On the back + 12V DC must be supplied as operating voltage. For the power supply units, we opted for linear power supplies because we have made the best experience with these without interference. For a distribution unit with 4 slots, a power supply with 12V 1A is sufficient &#8211; each distribution block takes about 55 mA, an active antenna up to 150 mA, so even with &#8220;full load&#8221; a power supply with 1 A is sufficient. The distributor was tested with various well-known active and passive antennas, including a PA0RDT MiniWhip, active loops, long wires and T2FD.<\/p>\n<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-9.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-40822\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-9.jpg\" alt=\"\" width=\"720\" height=\"960\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-9.jpg 720w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-9-225x300.jpg 225w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-9-624x832.jpg 624w\" sizes=\"auto, (max-width: 720px) 100vw, 720px\" \/><\/a><\/p>\n<p>Due to the wide input voltage range, the module can handle nearly any antenna. The cost for a distributor for 4 antennas amounts\u00a0 (depending on the version: housing, sockets, switches, power supply, etc.) to about 700-1000 \u20ac. That may seem a lot at first glance. However, taking into account that a simple 5-gang distributor from mass production costs already around 250 \u00ac, the cost of the distribution of 4 antennas to each up to 12 outputs are not that much. The Friends of Radio NRW use two of these distribution units for SWL camps.<\/p>\n<p>If you are interested in building one, please contact the author (<a href=\"mailto:dh4jg@darc.de\" target=\"_blank\" rel=\"noopener noreferrer\">dh4jg@darc.de<\/a>) for further information. The development history of the distribution unit is also available at <a href=\"http:\/\/www.dx-unlimited.eu\" target=\"_blank\" rel=\"noopener noreferrer\">www.dx-unlimited.eu<\/a>.<\/p>\n<hr \/>\n<p><em><strong>Wow!\u00a0 What a beautifully engineered antenna distribution solution, Joachim!\u00a0 I love how you worked together to sort out all of the requirements for your system then build it for ultimate performance and flexibility.\u00a0 No doubt, you and your colleagues at\u00a0 Radiofreunde NRW posses a lot of design and engineering skills!\u00a0 Simply amazing and thank you for sharing your design with the radio community!<\/strong><\/em><\/p>\n<p style=\"text-align: center;\"><strong>Contact <a href=\"dh4jg@darc.de\" target=\"_blank\" rel=\"noopener noreferrer\">Joachim<\/a> for more details and check out notes and discussion at <a href=\"http:\/\/www.dx-unlimited.eu\" target=\"_blank\" rel=\"noopener noreferrer\">www.dx-unlimited.eu<\/a> (may require registration).<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Many thanks to SWLing Post contributor, Joachim von Geisau (DH4JG), for the following guest post: Signal distribution at SWL camps: The new JK-1000 HF distributor by Joachim von Geisau (DH4JG) The Friends of Radio NRW &#8211; an independent group of shortwave listeners and radio amateurs in Germany &#8211; have been organizing 2-3 SWL camps per [&hellip;]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[4199,3607,399,3194,627,2436,433,3,43],"tags":[8300,2043,1643,2224,4342,4105,8160,8159],"class_list":["post-41879","post","type-post","status-publish","format-standard","hentry","category-accessories","category-antennas","category-dxpeditions","category-guest-posts","category-how-to","category-longwave","category-mediumwave","category-news","category-shortwave-radio","tag-antenna-distribution","tag-antenna-splitter","tag-antennas","tag-dxpedition","tag-guest-posts","tag-how-to","tag-joachim-geisau","tag-radiofreunde-nrw"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-aTt","jetpack-related-posts":[{"id":40801,"url":"https:\/\/swling.com\/blog\/2019\/11\/photos-from-the-radiofreunde-nrw-dxpedition\/","url_meta":{"origin":41879,"position":0},"title":"Photos from the Radiofreunde NRW DXpedition","author":"Thomas","date":"November 27, 2019","format":false,"excerpt":"After recently checking out a number of photos on the Radiofreunde NRW Facebook page, I asked if a member of this group could give me a little more detail about their DXpeditions. Many thanks to Joachim Geisau who writes: Radiofreunde NRW is an independent association of SWL, radio amateurs and\u2026","rel":"","context":"In &quot;DXpeditions&quot;","block_context":{"text":"DXpeditions","link":"https:\/\/swling.com\/blog\/category\/dxpeditions\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-8.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-8.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-8.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Radiofreunde-NRW-8.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":49295,"url":"https:\/\/swling.com\/blog\/2021\/06\/jock-designs-a-horizontal-room-loop-to-cope-with-reception-issues\/","url_meta":{"origin":41879,"position":1},"title":"Jock designs a Horizontal Room Loop to cope with reception issues","author":"Thomas","date":"June 17, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post: Got reception issues? An idea worth considering: the \u201cHorizontal Room Loop.\u201d by Jock Elliott (KB2GOM) When my radio room was in the front of the house (on the east side), it was easy to run a\u2026","rel":"","context":"In &quot;Antennas&quot;","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/06\/Jock-Elliott-Horizontal-Room-Loop-1.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/06\/Jock-Elliott-Horizontal-Room-Loop-1.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/06\/Jock-Elliott-Horizontal-Room-Loop-1.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/06\/Jock-Elliott-Horizontal-Room-Loop-1.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/06\/Jock-Elliott-Horizontal-Room-Loop-1.jpeg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":10696,"url":"https:\/\/swling.com\/blog\/2015\/04\/portable-antennas-par-electronics-ef-swl\/","url_meta":{"origin":41879,"position":2},"title":"Portable antennas: a review of the Par Electronics EF-SWL","author":"Thomas","date":"April 3, 2015","format":false,"excerpt":"Last August and part of September,\u00a0I traveled\u00a0through the US with the CommRadio CR-1 and a couple of portable antennas: the\u00a0Par Electronics EF-SWL and \u00a0NASA PA-30. I had the opportunity to try both in the field, and took notes as I used them. Following is a short review of the\u00a0Par Electronics\u2026","rel":"","context":"In &quot;Antennas&quot;","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"The EF-SWL ready to deploy.","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/09\/ParElectronics_EFSWL.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/09\/ParElectronics_EFSWL.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/09\/ParElectronics_EFSWL.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":52581,"url":"https:\/\/swling.com\/blog\/2022\/05\/the-satellit-800-the-tecsun-pl-880-and-two-indoor-antennas-an-afternoon-of-experimentation\/","url_meta":{"origin":41879,"position":3},"title":"The Satellit 800, the Tecsun PL-880, and two indoor antennas \u2013 an afternoon of experimentation","author":"Thomas","date":"May 1, 2022","format":false,"excerpt":"Many thanks to\u00a0SWLing Post\u00a0contributor,\u00a0Jock Elliott, who shares the following guest post: The Satellit 800, the Tecsun PL-880, and two indoor antennas \u2013 an afternoon of experimentation By Jock Elliott, KB2GOM A search for \u201cshortwave listening antennas\u201d on the internet landed me on the page for the Par EndFedz\u00ae EF-SWL receive\u2026","rel":"","context":"In &quot;Antennas&quot;","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/04\/TG6-PL880-wire-antenna-001-001-Medium.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/04\/TG6-PL880-wire-antenna-001-001-Medium.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/04\/TG6-PL880-wire-antenna-001-001-Medium.jpeg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":47597,"url":"https:\/\/swling.com\/blog\/2021\/02\/rob-compares-horizontal-and-vertical-swl-random-wire-antennas\/","url_meta":{"origin":41879,"position":4},"title":"Rob compares horizontal and vertical SWL random wire antennas","author":"Thomas","date":"February 3, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Rob Zingarelli, who shares the following guest post that originally appeared on his blog in October, 2020: Shortwave Antenna: Vertical or Horizontal? by Rob Zingarelli This is a question that has circled around on the fringes of my consciousness for years now, but one\u2026","rel":"","context":"In &quot;Antennas&quot;","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/02\/Rob-Zingarelli-Antenna.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":46267,"url":"https:\/\/swling.com\/blog\/2020\/11\/steve-builds-a-simple-swl-antenna-tuner-that-pairs-brilliantly-with-the-belka-dx\/","url_meta":{"origin":41879,"position":5},"title":"Steve builds a simple SWL antenna tuner that pairs brilliantly with the Belka-DX","author":"Thomas","date":"November 1, 2020","format":false,"excerpt":"Many thanks to SWLing Post contributor, Steve Allen (KZ4TN), who shares the following guest post: A Simple Antenna Tuner for SWL Radios by Steve Allen, KZ4TN After reading 13DKA\u2019s excellent review of the Belka-DSP on SWLing.com a few weeks ago I knew I had to have one! The size, features,\u2026","rel":"","context":"In &quot;Accessories&quot;","block_context":{"text":"Accessories","link":"https:\/\/swling.com\/blog\/category\/accessories\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/10\/KZ4TN-Simple-Antenna-Tuner.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/41879","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=41879"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/41879\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=41879"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=41879"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=41879"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}