8782	2013-07-05 11:03:25	Chris Trask	Active Monopole Antenna Amplifier
Message	Date	From	Subject
Four and a half years ago I published an online article on active monopole antenna amplifiers. Lately there has been some renewed interest in the subject, so I pulled out all of the notes I had made since then and revised the article: http://www.home.earthlink.net/~christrask/Complementar20%Push-Pull20%Amplifiers.pdf Most of the changes are the result of comments and suggestions by people who have built my amplifiers, and others are a result of ideas gathered from commercial products. Chris Trask N7ZWY / WDX3HLB http://www.home.earthlink.net/~christrask/
8783	2013-07-05 14:01:35	Alberto I2PHD	Re: Active Monopole Antenna Amplifier

8784	2013-07-05 14:18:48	Chris Trask	Re: Active Monopole Antenna Amplifier
> >> / Four and a half years ago I published an online article on active monopole antenna amplifiers.// >> //Lately there has been some renewed interest in the subject, so I pulled out all of the notes// >> //I had made since then and revised the article: >> >> //http://www.home.earthlink.net/~christrask/Complementar20%Push-Pull20%Amplifiers.pdf// >> >> / >That URL is badly malformed, and at least Firefox does not accept it. >Modifying it in this way made it work : > >http://www.home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf > I typed in the "20%" manually, and it should have been "%20". > >Additionally, IMHO, Fig. 3 seems to be upside down, > My Tektronix 575 displays PNP devices upside down, and I keep it that way so as to distinguish them from NPN devices. > >and in Fig. 12 the markings of T1 and T2 are perhaps swapped. > Yes, those are backwards. I'll take care of that shortly. Chris
8785	2013-07-05 14:43:03	Chris Trask	Re: Active Monopole Antenna Amplifier
> > Four and a half years ago I published an online article on active monopole >antenna amplifiers. Lately there has been some renewed interest in the subject, >so I pulled out all of the notes I had made since then and revised the article: > >http://www.home.earthlink.net/~christrask/Complementar20%Push-Pull20%Amplifiers.pdf > > Most of the changes are the result of comments and suggestions by people who >have built my amplifiers, and others are a result of ideas gathered from commercial >products. > >Chris Trask >N7ZWY / WDX3HLB >http://www.home.earthlink.net/~christrask/ > Ooops! That URL should have been: http://www.home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf Chris
8794	2013-07-07 20:21:31	Gene Dorcas	Re: Active Monopole Antenna Amplifier
The link wouldn’t work but I went to your web and maybe its all there??? I have for some time now thought that I could do better with a receive only antenna. I either run my 5w qrp rig or my FT-450D into a trap vertical. It seems to work very well when calling a DX station but I’ve often wondered what kind of compromise that trap vertical is for receiving. Do you think an active whip or dipole as a separate receiving antenna would yield any improvement??? I’ve been looking at the active antenna by Clifton labs and then I found your paper(s). Do u have any suggestions??? Thanks, Gene, W5DOR gene@w5dor.com www.w5dor.com
8795	2013-07-08 06:13:59	Chris Trask	Re: Active Monopole Antenna Amplifier
> >The link wouldn’t work but I went to your web and maybe its all there??? > It's listed on the web page, but I've attached a copy for you. Seems I can't properly write a URL these days. > >I have for some time now thought that I could do better with a receive only antenna. I either run my 5w >qrp rig or my FT-450D into a trap vertical. It seems to work very well when calling a DX station but >I’ve often wondered what kind of compromise that trap vertical is for receiving. Do you think an active >whip or dipole as a separate receiving antenna would yield any improvement??? I’ve been looking at the >active antenna by Clifton labs and then I found your paper(s). > >Do u have any suggestions??? > There's really no substitute for a full 1/4-wave vertical antenna. Active monopoles are convenient at low frequencies where tall verticals are impractical. They're also convenient in places where antennas are not allowed due to zoning or HOA rules. Chris [Non-text portions of this message have been removed]