+++++++++++++++++++ Date: Sat, 11 May 2002 17:48:23 -0700 From: Wayne Burdick Organization: Elecraft To: Steve Jackson Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] 136 kHz band Steve Jackson wrote: > > Here's hoping that Elecraft makes a kit transverter for the 136 kHz band. Hi Steve, Nice idea for a product. We have a few other irons in the fire in the near term. I wouldn't be surprised to see one of our customers adapt an existing 136 kHz design for use with the K2 (hint, hint). The K2's programmable transverter band feature would work well here. Since the RF band for any of the three transverters can be set *below* the selected I.F., you could have the K2's display show the actual operating frequency in the 136 kHz range. You can even fine-tune the offset +/- 9.99 kHz, so you don't need fine frequency control of the oscillar used in the transverter. 73, Wayne N6KR -- original message -- From: "Steve Jackson" To: Date: Sat, 11 May 2002 20:30:10 -0400 Subject: [Elecraft] 136 kHz band Here's hoping that Elecraft makes a kit transverter for the 136 kHz band. It should be packaged in the EC2 case, and have an AuxBus loop-through for control, and two DC power mechanisms: one, a pair of the existing DC coaxial jacks, so that the DC can loop to the K2 exciter, using a male-male coaxial plug cable. There should also be an optional power amplifier deck, similar to the new 100W amp for the K2. Extensive noise filtering will be in order. This is best done digitally, today, so I don't know how long Elecraft will be able to keep making kits with no SMD parts ... I suspect this is going to happen eventually. I don't mind building with SMD but I don't know how well that will sell to other hams (beyond a relatively small core group, many of whom I bet are on this reflector!). I am guessing the new band will have an ERP limitation, probably on the order of 5W or so, rather than a transmitter power limit. With an antenna efficiency of 5%, you can start with a 10W exciter and go to 100W or so with the amp. Since no bandswitching is needed, all this should be an easy layout and relatively low in cost. The transverter code is already in the K2 firmware; well, mostly. Figure a base cost of $199 plus the optional noise filtering option ($59) and the amp ($149). +++++++++++++++++++ To: elecraft at mailman.qth.net Date: Sun, 12 May 2002 09:14:35 -0500 From: n4so at juno.com Subject: [Elecraft] 136 kHz Band --Already been done by other groups such as AMRAD and David Curry and other LowFERs. You must have missed QST for April 2002. Frank Gentges, K0BRA, Steve Ratzlaff, AA7U, AMRAD Low Frequency Upconverter, QST, April 2002, p. 34 converts the entire VLF/LF band up to a selected conversion frequency such as 4 Mhz, for example, placing the tuning range 4 to 4.5 mHz and would put 136 kHz on 4136 kHz on the dial. Details are on page 38. Built in three modules, the Low Pass Filter, the actual LF converter and the Power Supply. www.amrad.org/projects/lf/rx www.lwca.org/library/articles/kf5cq/lfconvtr.htm AMRAD project refers to an article by Tim Brannon, KF5CQ, "A High Performance Low frequency Converter". LowFER= Low Frequency Experimental Radio Other sources: David Curry, WD4PLI and his company did have built units for sale-- David Curry, WD4PLI, Build Your Own LowFER Transceiver, QST, April, 1994, page 26, shows a circuit and schematic for a 160 to 190 kHz transceiver and I think he sold a unit based on this article. The Upconverter idea seems to be a better idea and would give better results. CQ Magazine, Sept. 1997, pg. 40 And there is a LowFER mailing list: lowfer.txt lowfer at mailman.qsl.net subscribe lowfer E-mail or via the Web page mentioned below: Here is info on joining the LowFer reflector/mailing list From: lowfer-request at mailman.qth.net Date: Sat, 2 Mar 2002 06:41:11 -0500 (EST) Subject: Welcome to the "Lowfer" mailing list Welcome to the Lowfer at mailman.qth.net mailing list! To post to this list, send your email to: lowfer at mailman.qth.net General information about the mailing list is at: http://mailman.qth.net/mailman/listinfo/lowfer If you ever want to unsubscribe or change your options (eg, switch to or from digest mode, change your password, etc.), visit your subscription page at: http://mailman.qth.net/mailman/options/lowfer/n4so%40juno.com You can also make such adjustments via email by sending a message to: Lowfer-request at mailman.qth.net +++++++++++++++++ From: "Dave Sergeant" To: "elecraft" Date: Mon, 13 May 2002 11:15:21 +0100 Subject: [Elecraft] 136kHz transverter You will find a transverter design for 136kHz on my web site (address below). I have used this with my FT101ZD for some time - it transverts to 10MHz, and should work with the K2 with the addition of an interface to drive the aerial change over relay. Note that although the K2 is designed for transverter use from 7, 14 and 28 this is just for the nicety of a direct readout at the transverted frequency. You will also find a lot of useful information about 136 on my site, and links to other 136 sites. Since completing my K2 I have understandably not done much on that band. In any case activity in the UK on CW has dropped to virtually nothing after the novelty has worn off, and most activity has moved to the various digital modes which don't interest me one iota. I wish the US amateurs success on the band once they have received the official go ahead. 73s Dave G3YMC dsergeant at iee.org dsergeant at btinternet.com http://www.dsergeant.btinternet.co.uk +++++++++++++++++++++