{"id":24798,"date":"2017-03-24T16:26:23","date_gmt":"2017-03-24T20:26:23","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=24798"},"modified":"2017-03-24T16:26:23","modified_gmt":"2017-03-24T20:26:23","slug":"dan-sheds-light-on-various-hammarlund-sp-600-models","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2017\/03\/dan-sheds-light-on-various-hammarlund-sp-600-models\/","title":{"rendered":"Dan sheds light on various Hammarlund SP-600 models"},"content":{"rendered":"

\"\"<\/a><\/p>\n

Many thanks to SWLing Post<\/em> contributor, Daniel Hawkins, who leaves the following comment in reply to our previous post about the Northern Radio SP-600<\/a> and discussion about\u00a0diversity operation. Dan writes:<\/p>\n

Diversity operation: two or more receivers and antennas used to copy CW or RTTY from one or more transmitters.<\/p>\n

Most of the Hammarlund SP-600s were models built for diversity use including the well-known JX-17, the most common SP-600. Diversity models can be used as single receivers. In this eBay example Northern Radio has modified a SP-600 J-11 for diversity use.<\/p>\n

SP-600 nomenclature: J means joint army\/navy (JAN) mil-spec components. L means low frequency. X means crystal frequency control in addition to VFO. My SP-600 is a JX-21, which is not a diversity model. Higher model numbers do not necessarily mean later production dates. All SP-600s use the same serial number sequence regardless of model. Somewhere between serial numbers 15,000 and 17,000 (mid 1950’s) Hammarlund stopped using molded black beauty capacitors and switched to installing ceramic capacitors.<\/p>\n

The two-digit model numbers indicate model types. JX-1, 7, 10 and 21 were similar non-diversity receivers. SP-600s built for military contracts will have an additional tag showing the military model number(s).<\/p>\n

Here is a great page showing Northern Radio modified SP-600s in action with accompanying Northern Radio RTTY gear.<\/p>\n

http:\/\/www.navy-radio.com\/rcvrs\/frr28.htm<\/a><\/p><\/blockquote>\n

Thanks for the primer, Dan! I believe I have one of the X models with crystal control, but I’ll need to verify once back home. Any other SP-600 owners out there in the Post<\/em> readership?<\/p>\n","protected":false},"excerpt":{"rendered":"

Many thanks to SWLing Post contributor, Daniel Hawkins, who leaves the following comment in reply to our previous post about the Northern Radio SP-600 and discussion about\u00a0diversity operation. Dan writes: Diversity operation: two or more receivers and antennas used to copy CW or RTTY from one or more transmitters. Most of the Hammarlund SP-600s were […]<\/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":[1271,545,3,305,43,4796],"tags":[5259,2897,4344,6049],"class_list":["post-24798","post","type-post","status-publish","format-standard","hentry","category-boat-anchors-2","category-ham-radio","category-news","category-nostalgia","category-shortwave-radio","category-vintage-radio","tag-daniel-hawkins","tag-hammarlund","tag-hammarlund-sp-600","tag-northern-radio-sp-600"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-6rY","jetpack-related-posts":[{"id":20010,"url":"https:\/\/swling.com\/blog\/2016\/07\/video-dan-listens-to-rnzis-sunday-night-with-grant-walker-on-a-hammarlund-sp-600\/","url_meta":{"origin":24798,"position":0},"title":"Video: Dan listens to RNZI’s Sunday Night with Grant Walker on a Hammarlund SP-600","author":"Thomas","date":"July 21, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor,\u00a0Daniel Hawkins, who writes: One of my favorite Radio New Zealand International programs is Sunday Night with Grant Walker. This program is heard on RNZ in New Zealand from 8:06-10:00 p.m. and is run at the same time on RNZI. Sunday Night features hit oldies\u2026","rel":"","context":"In "Guest Posts"","block_context":{"text":"Guest Posts","link":"https:\/\/swling.com\/blog\/category\/guest-posts\/"},"img":{"alt_text":"DanH-SP-600","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/07\/DanH-SP-600.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/07\/DanH-SP-600.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/07\/DanH-SP-600.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":32398,"url":"https:\/\/swling.com\/blog\/2018\/05\/dan-spots-the-ultra-rare-hammarlund-sp-600-jx21a-on-ebay\/","url_meta":{"origin":24798,"position":1},"title":"Dan spots the ultra rare Hammarlund SP-600 JX21A on eBay","author":"Thomas","date":"May 22, 2018","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dan Robinson, who discovered a very rareHammarlund SP-600 JX21A on eBay. Dan writes: Collectors of classic boatanchor gear know what has been probably the rarest of tube sets year after year, decade after decade. That set is the Hammarlund SP-600 JX21A. While there have\u2026","rel":"","context":"In "Boat Anchors"","block_context":{"text":"Boat Anchors","link":"https:\/\/swling.com\/blog\/category\/boat-anchors-2\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/Hammarlund-SP-600-JX25A-1024x648.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/Hammarlund-SP-600-JX25A-1024x648.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/Hammarlund-SP-600-JX25A-1024x648.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":46905,"url":"https:\/\/swling.com\/blog\/2020\/12\/dans-respect-for-hammarlund-and-the-sp-600-series\/","url_meta":{"origin":24798,"position":2},"title":"Dan’s respect for Hammarlund and the SP-600 series","author":"Thomas","date":"December 13, 2020","format":false,"excerpt":"Many thanks to SWLing Post contributor, DanH, who shares the following comment in response to this news article from the Citizen Times featured in Radio Waves yesterday: Here are my thanks to members of the Amateur Radio community and The News-Record & Sentinel for remembering the legacy of Hammarlund Manufacturing\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/05\/Hammarlund-SP-600.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/05\/Hammarlund-SP-600.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/05\/Hammarlund-SP-600.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/05\/Hammarlund-SP-600.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":24789,"url":"https:\/\/swling.com\/blog\/2017\/03\/exceedingly-rare-northern-radio-modified-sp-600\/","url_meta":{"origin":24798,"position":3},"title":"Exceedingly rare Northern Radio modified SP-600","author":"Thomas","date":"March 23, 2017","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dan Robinson, who writes: Those of us who still use SP-600s, and those of us who once did but can't deal with them in retirement, lust after some of the rarer versions of the radio. This is one of them, the Northern Radio modified\u2026","rel":"","context":"In "Boat Anchors"","block_context":{"text":"Boat Anchors","link":"https:\/\/swling.com\/blog\/category\/boat-anchors-2\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Hammarlund-SP-600-J-1024x600.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Hammarlund-SP-600-J-1024x600.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Hammarlund-SP-600-J-1024x600.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":18205,"url":"https:\/\/swling.com\/blog\/2016\/04\/ebay-find-rack-of-classic-receivers\/","url_meta":{"origin":24798,"position":4},"title":"eBay find: Rack of classic receivers","author":"Thomas","date":"April 10, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dan Robinson, who shared a link to this rack of classic cold war era receivers. The starting bid is $943.75 and there is no shipping cost as it's local pickup only (no surprise there). Here's the description from eBay: LOCAL PICK UP ONLY Paso\u2026","rel":"","context":"In "Boat Anchors"","block_context":{"text":"Boat Anchors","link":"https:\/\/swling.com\/blog\/category\/boat-anchors-2\/"},"img":{"alt_text":"Rack-Gear","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/04\/Rack-Gear-768x1024.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/04\/Rack-Gear-768x1024.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/04\/Rack-Gear-768x1024.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":35845,"url":"https:\/\/swling.com\/blog\/2019\/02\/dan-spots-a-hammarlund-sp-600-in-the-shape-of-water\/","url_meta":{"origin":24798,"position":5},"title":"Dan spots a Hammarlund SP-600 in “The Shape of Water”","author":"Thomas","date":"February 3, 2019","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dan Robinson, who writes: Did anyone ever notice this [in The Shape of Water]? I have not seen the film yet, but how could we miss that classic Cold War rig?! Very cool--thanks for sharing, Dan! I\u2019ll add this post\u00a0to\u00a0our archive of radios in\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/02\/Shape-Of-Water-SP-600.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/02\/Shape-Of-Water-SP-600.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/02\/Shape-Of-Water-SP-600.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/02\/Shape-Of-Water-SP-600.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/24798","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=24798"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/24798\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=24798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=24798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=24798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}