tag:blogger.com,1999:blog-513094667326816455.post7207730017764823096..comments2023-06-01T08:28:20.863+01:00Comments on M1KTA's QRP ham radio blog: Comments on the Chinese ATUUnknownnoreply@blogger.comBlogger23125tag:blogger.com,1999:blog-513094667326816455.post-63637258678061224492020-06-29T18:13:32.482+01:002020-06-29T18:13:32.482+01:00Go to https://archive.org/details/73-magazine-1995...Go to https://archive.org/details/73-magazine-1995-10 and read about the QRP Delight.Dom M1KTAhttps://www.blogger.com/profile/09611005722909739998noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-49008654257164088102020-04-20T19:22:32.340+01:002020-04-20T19:22:32.340+01:00Hi Guys,
Please I 1 of the qrp tuner but the red ...Hi Guys,<br /> Please I 1 of the qrp tuner but the red led indicator does not show or work some where I heard that there is a mod to the board but do not know please if there is please do let me know wopuld like it to work and the daigram of it,<br />many thanks,<br />PieterAnonymoushttps://www.blogger.com/profile/03405190640815710302noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-49613045511632183642019-08-08T15:17:10.406+01:002019-08-08T15:17:10.406+01:00I had a slight problem with the knob screws not be...I had a slight problem with the knob screws not being secure on the caps, so I added a very small drop of blue 9removable) lock-tite to hold them better.<br /><br />On the variable caps, I read 173 PF to 97.7 PF from center to either outer tab, and when the outer tabs are joined, I read, 245 PF to 151 PF, using my Knight K-240C LCR meter.<br /><br />I found your site informative and the notes great. <br /><br />I like these kits and modded mine to use the box and SWR indicator assembly with a 49:1 (half wave end fed) balun and kept one cap to adjust it with. <br /><br />The switch and coil assembly I put in another box with the second cap to use as a second antenna tuner.<br />Possumnhttps://www.blogger.com/profile/17411725057785544813noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-68159706790889582212019-08-08T15:06:24.498+01:002019-08-08T15:06:24.498+01:00I found a slight problem with the knob screws not ...I found a slight problem with the knob screws not staying secure in the variable capacitors, so I added a very small drop of blue (removable) lock-tite on the threads to secure them better. <br /><br />On the capacitor measurements, I read 98pf to 170 pf from center to either outer tab, When outer tabs are joined I read 245pf to 151 PF.<br /><br />I like the kit just for the parts, and found your article and notes great reading. <br /><br />I modded my kit to use the SWR indicator with a 49 to 1 end fed half wave balun instead of the switched coil, and kept one cap in the box to adjust it with. And put the switched coil assembly in another box for use as a second tuner.Possumnhttps://www.blogger.com/profile/17411725057785544813noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-70961516765990279212018-08-25T15:08:15.918+01:002018-08-25T15:08:15.918+01:00Been using one of these that I build for backpacki...Been using one of these that I build for backpacking etc for 2 years. Don't go over 10 watts.! Anonymoushttps://www.blogger.com/profile/04932177338482578579noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-33981994988444884852018-02-12T16:43:32.380+00:002018-02-12T16:43:32.380+00:00About the toroids as someone asked..
The schemati...About the toroids as someone asked..<br /><br />The schematic shows the two clearly see the main section image<br /><br />The grey/shiney or black FT37-43 about 1/2" diameter is in the VSWR<br /><br />The RED T106-2 about 1" diameter is in the ATU.<br /><br />M1KTAhttps://www.blogger.com/profile/05944098903387301523noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-76758308260632607342017-05-03T10:09:16.585+01:002017-05-03T10:09:16.585+01:00hi everyone..i am a new builder and new to HF QRP....hi everyone..i am a new builder and new to HF QRP. Ive tried to assemble the kit based on the instructions and reference to this blog and youtube. however, while installing the selector switch to its knob, the selector switch popped and a small ball bearing came off and it seems not to select anymore. I have manage to find a replacement on ebay. For the capacitors, the small nut which goes between the knob and the capacitor is too large for the screw size provided therefore i cant seem to connect the knobs to the caps. Any ideas on this? I would like to also inquire, what are the specifications of the two variable capacitors as i would want to purchase replacement. (specs and capacitance).<br /><br />It would be very helpful if I can get these information from you experienced HAMs.<br /><br />Thank you very much.<br />9W2JST<br />Justin Goonting<br />MalaysiaJustin Goontingnoreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-30943663634494679882017-04-14T19:52:49.777+01:002017-04-14T19:52:49.777+01:00My kit came with countersunk screws for the variab...My kit came with countersunk screws for the variable capacitors so I counter-sank the holes and possibly butchered the capacitors. With the 2 sections in parallel each capacitor measures a total of 42pF, much less than I would have expected. Maybe I've been provided with fm rather than am capacitors? Has anyone else measured theirs?<br />Alan<br />M/VK5ZFJ <br />ps the coils is 16.3uH end to end Alanhttps://www.blogger.com/profile/06890142337853277928noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-37918289100504481562016-06-16T08:54:38.790+01:002016-06-16T08:54:38.790+01:00Sverre/Thomas.... Thanks both for comments. I am n...Sverre/Thomas.... Thanks both for comments. I am not suggesting any deviation from the Chinese tuner on these pages, I included the build instructions in a slightly clearer form as some were challenged with the Chinese instructions. This page is all about how to build THIS one not create your own. We all know how to obtain details from other references for Pi and T tuners using a couple of poly-variable caps and an inductor, there are probably 100's of variations in the home-brew space this page is not about that. I am sure I might have a page that talks about other tuner variations.<br /><br />For those that need/want a cheap tuner this seems to fit the bill.<br /><br />72<br /><br />Dom<br />M1KTAM1KTAhttps://www.blogger.com/profile/05944098903387301523noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-76836624519942591592016-06-16T08:38:09.721+01:002016-06-16T08:38:09.721+01:00I looked up the 1970 QST article by DeMaw. There a...I looked up the 1970 QST article by DeMaw. There are similarities: It contains two variable capacitor and a variable inductor. But the DeMaw article has them in a pi-arrangement, while the Chinese tuner has them in a T-arrangement. So they are not really similar. But were you perhaps suggesting that it would be a good idea to rearrange the Chinese tuner into a pi?<br /><br />Sverre<br />LA3ZASverre Holmhttps://www.blogger.com/profile/08306221557326542499noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-26205159169493760132016-06-15T23:51:33.454+01:002016-06-15T23:51:33.454+01:00Great reference! Thanks!
No kidding about having...Great reference! Thanks!<br /><br />No kidding about having readable instructions!<br /><br />Kevin<br />K4IVEKevin E. Iveyhttps://www.blogger.com/profile/00939361722101993235noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-61522510185702110912016-06-15T02:56:00.704+01:002016-06-15T02:56:00.704+01:00At current prices, the price of this tuner is clos...At current prices, the price of this tuner is close to the cost of the parts, making it a good deal. And the case is high quality.<br />The tuner is essentially identical with the tuner featured in the QST article:<br />"A QRP Console" DeMaw, QST, Sept. 1970, p. 23-25.<br />The SWR meter is a creation of Tayloe.<br />http://www.qrpkits.com/swrindicator.html<br />It's probably better to build this tuner according to these two sources: Same parts.<br />At least the builder will have good directions.Thomashttps://www.blogger.com/profile/08513989804663798077noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-4768891395930056582016-06-01T15:12:22.488+01:002016-06-01T15:12:22.488+01:00The original name for this kit is quite simply:手動天...The original name for this kit is quite simply:手動天調套件<br />The three parts/words are:<br />手動=manual<br />天調=antenna tuner<br />套件=kit<br />Problem is that when they translated it they separated 天 and 調. The character 天 means "heaven", but also "day", while 調 means "tone" but also "tune".<br /><br />So, there you go. Simply a hiccup during translation. Blame it on Google. 73 de BX2ABT<br />Hans (BX2ABTnoreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-30842935862845223532016-03-22T10:12:16.941+00:002016-03-22T10:12:16.941+00:00Mine works, but the LED gets brighter when the SWR...Mine works, but the LED gets brighter when the SWR goes low and vice versa, i.e. the wrong way around. I've checked and I have the in out connections correct to the circuit board and the secondary toroid the right way around. Not the LED itself, 'cause if it was the wrong way around it wouldn't conduct/light.<br /><br />I've obviously done something wrong, which must be simple, but I'm having a senior moment and it isn't coming to me.RHnoreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-30002707428740701982016-02-25T15:48:33.016+00:002016-02-25T15:48:33.016+00:00I'm pretty sure "Days" is supposed t...I'm pretty sure "Days" is supposed to be "DIY." The Chinese translation bot choked on the acronym...<br /><br />Kevin E. Iveyhttps://www.blogger.com/profile/00939361722101993235noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-65187254348406710402016-02-25T15:40:35.772+00:002016-02-25T15:40:35.772+00:00The circuit I have added as an image.
I have no i...The circuit I have added as an image.<br /><br />I have no idea what "Days" in the translation meant as far as the original author is concerned, probably meant Days. I suspect the title should be something like ... QRP Field Day Antenna tuner.... might make more sense.M1KTAhttps://www.blogger.com/profile/05944098903387301523noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-86316344442845425172015-11-17T03:48:11.968+00:002015-11-17T03:48:11.968+00:00Any idea what "QRP Manual Days Antenna Tuner ...Any idea what "QRP Manual Days Antenna Tuner Tune DIY Kits" means? What is a "Days?"<br /><br />I can understand the usual bad translation and can't figure out what they are trying to say...<br /><br />Thanks!Kevin E. Iveyhttps://www.blogger.com/profile/00939361722101993235noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-20119176335902187612014-12-20T21:26:45.698+00:002014-12-20T21:26:45.698+00:00It appears that the file on your box account is no...It appears that the file on your box account is no longer available. Do you have another source for the schematic?Roy Appletonhttps://www.blogger.com/profile/18130507944929559514noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-31669278955714271022014-09-27T21:39:10.994+01:002014-09-27T21:39:10.994+01:00I had the same experience as Sverre Holm. The capa...I had the same experience as Sverre Holm. The capacitor mounting screws were way too long and destroyed the variable capacitors. Luckily the local emporium had replacements. The build instructions were strange in the extreme, I ended up building mine from the photos<br /><br />dave<br />ww2rg4frehttps://www.blogger.com/profile/14201949618514029864noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-63475734138134960202014-07-24T10:53:00.838+01:002014-07-24T10:53:00.838+01:00Martin,
The tuning is very sharp.
I've tried...Martin,<br /><br />The tuning is very sharp.<br /><br />I've tried it on a couple of different dipoles 15m, 20m and 40m. <br /><br />Verticals and long wires again it worked but not on 80m, did not seem to have enough C.M1KTAhttps://www.blogger.com/profile/05944098903387301523noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-54708272416234480612014-07-24T08:10:50.749+01:002014-07-24T08:10:50.749+01:00Hi, I was just wondering if you had any comments o...Hi, I was just wondering if you had any comments on how well it worked and with what antenna configurations?<br /><br />Martin<br />G0PJOMartinhttps://www.blogger.com/profile/08829986979481655908noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-45734991155820758272014-06-02T20:20:46.720+01:002014-06-02T20:20:46.720+01:00One thing worth mentioning that happened to me, is...One thing worth mentioning that happened to me, is that the two screws for mounting each of the variable capacitors were too long. The result was that they interfered with the moving plates of the capacitor and I have probably ruined both of them. There was no warning of this in the manual, so beware anyone who buys this kitSverre Holmhttps://www.blogger.com/profile/08306221557326542499noreply@blogger.comtag:blogger.com,1999:blog-513094667326816455.post-19316587146079480072014-05-25T19:41:12.020+01:002014-05-25T19:41:12.020+01:00W5CYF has done two excellent videos constructing t...W5CYF has done two excellent videos constructing this ATU:<br /><br />The $20 eBay Antenna Tuner Kit Assembly and Review - Part 1 :<br /><br />http://www.youtube.com/watch?v=jdFTwGv-CZY<br /><br />Part 2<br />http://www.youtube.com/watch?v=hYeb-XN80FA<br /><br />73 G1KQHG1KQHhttps://www.blogger.com/profile/04158573334769780015noreply@blogger.com