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The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: But when we talk of the *loaded* Q of a (R)LC circuit, then your reasoning is correct. Unless its going into a glass display case .. then it will be (loaded rlc) large Q values are not too helpful :) [...] Content analysis details: (0.2 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [80.12.242.59 listed in list.dnswl.org] 0.2 STOX_REPLY_TYPE STOX_REPLY_TYPE X-Scan-Signature: 6bb858db23df2b82c4f5a8cb512b45b1 Subject: Re: LF: Re: how to increase the Q of my loading coil? Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d6018511f75e35c7a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none But when we talk of the *loaded* Q of a (R)LC circuit, then your reasoning is correct. Unless its going into a glass display case .. then it will be (loaded rlc) large Q values are not too helpful :) Look on 500 as a longer version of 160 , all these loss/q/bw problems are associated with much lower bands , G.. -------------------------------------------------- From: "Clemens Paul" Sent: Saturday, February 16, 2013 10:10 AM To: Subject: RE: LF: Re: how to increase the Q of my loading coil? > Graham, > >>I would think the higher the Q the higher the losses in >>such a coil , the bigger the circulating values . > > I would think this thinking is wrong. :-) > The higher the Q of the coil the lower are of course the losses in such a > coil. > We are dealing here with the *unloaded* Q of a component. > But when we talk of the *loaded* Q of a (R)LC circuit, then your reasoning > is correct. > The higher the *loaded circuit* Q the higher are the losses in all > involved > components including the coil due to increasing circulating currents. > Given a certain circuit increasing the Q of its components always will > reduce overall losses of that circuit. > > 73 > Clemens > DL4RAJ > >>-----Original Message----- >>From: owner-rsgb_lf_group@blacksheep.org >>[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Graham >>Sent: Friday, February 15, 2013 12:48 PM >>To: rsgb_lf_group@blacksheep.org >>Subject: Re: LF: Re: how to increase the Q of my loading coil? >> >>I would go along with that >> >>I would think the higher the Q the higher the losses in >>such a coil , the bigger the circulating values .. I look >>at 500 as the next band >>down from 160 , differing set of rules than coming up >>from 136 >>..Top coil , takes the voltage out of the shack / tuner >>house , while increasing the vertical amps , and yes, rain + >>Q = problems ! >> >>Ground is more important than the wire in the air or the >>tuner losses ....... all the old (now very old) marine >>installations only had 30 >>or 40 feet of vertical wire from the radio room roof >>to the top >>wire , but a few 1000's tons of iron and salt water to tune >>against >> >>GL-73-G.. >> >> >> >> >> >>-------------------------------------------------- >>From: "Alan Melia" >>Sent: Friday, February 15, 2013 1:28 AM >>To: >>Subject: LF: Re: how to increase the Q of my loading coil? >> >>> Why? I think you might need to look at the priorities first. >>> Experience says you will not notice the difference unless you have >>> tackled the problem of ground and environmental losses first (as >>> Stefan has done) The improvement obtained by improving the Q of the >>> loading coil may probably only increase the efficiency by a >>minute amount. >>> >>> You say you have a Q of 200 now.... this indicates a bandwidth of >>> about 2kHz meaning you will probably need to retune across >>the band. A >>> Q of 400 to 500 should be possible but unless the reduction in RF >>> resistance is a substantial fraction of the Rloss it is >>wasted effort. >>> It also means that your tuning will be very weather >>dependent. I feel >>> that unles you have situation of Rloss <15ohms you will >>barely notice >>> the difference......except a "flighty" system, difficult to keep >>> peaked, and possibly a number of fried PA devices when it goes wrong. >>> >>> Litz will improve the Q slightly, coil form factor needs to be right >>> as well, and Litz is a devil to work with (note "proper" Litz has >>> strand numbers are twisted in powers of 3, anything else is just >>> bundled and will not achieve the theoretical advantage) If you miss >>> one strand out of the soldered connection of the Litz you >>will lose a lot of the advantage. >>> >>> Top loading may well turn out to be more effective, but it >>all depends >>> on your partcular location, and you need to make measurements of the >>> antenna systtem, and possibly the field it generates, not guess >>> (though that is very seductive :-)) but in my experience is usually >>> wrong! ) >>> >>> You are right in that the best way is to make incremental >>improvements >>> to the antenna, but be very critical, weighing the cost in >>effort and >>> cash for the improvement .......what works for others may >>not work for you. >>> >>> Best of Luck >>> Alan >>> G3NYK >>> >>> ----- Original Message ----- >>> From: "Dimitrios Tsifakis" >>> To: >>> Sent: Friday, February 15, 2013 12:31 AM >>> Subject: LF: how to increase the Q of my loading coil? >>> >>> >>>> Hello group, >>>> >>>> I would like to increase the Q of my loading coil for 475 kHz. . It >>>> consists currently of a 20-litre plastic bucket with standard house >>>> 240V electrical wire (with PVC jacket). I measured the Q >>and found it >>>> to be about 220 (XL is about 2 kohm). I do have some Litz >>wire I can >>>> use. I also have a piece of large diameter (25 cm) storm >>water pipe, >>>> which I think is made of PVC. Would you recommend using a >>PVC former >>>> or should I look for a more exotic material >>(glass/porcelain)? Would >>>> you think the inter-turn capacitance is very detrimental and some >>>> exotic winding technique would yield better results? >>>> >>>> I understand that ground losses are bigger in my case than the >>>> inductor losses, but I would like to address the inductor first. >>>> >>>> 73, Dimitris VK1SV >>>> >>> >>> >> >> >> >>----- >>E-Mail ist virenfrei. >>Von AVG überprüft - www.avg.de >>Version: 2013.0.2899 / Virendatenbank: 2639/6104 - >>Ausgabedatum: 14.02.2013 >> > >