Mark all measure the radials they should be 102-108 inches if they have not ben cut or shortened. The radial construction for this style antenna consisted of two solid alu rods that threaded together. With the correct radial length just tune the length of the vertical element for lowest swr at your 10 meter frequency done. Depending on the vintage of your antenna the length may vary from 16-18 feet or 19-21 feet the coil inside the base were set up to match either a halfwave or 5/8wave vertical element. I have acouple that work great but cant measure since they are in the air. 73 SD
--- On Mon, 8/11/08, lenaw12 <[EMAIL PROTECTED]> wrote: From: lenaw12 <[EMAIL PROTECTED]> Subject: [Repeater-Builder] Re: Low Band Base Antenna Info Wanted To: [email protected] Date: Monday, August 11, 2008, 8:47 PM Hi Mark... How about you save some aluminum tubing by not cutting the radials too short for 10 meters....cut 4 radials about 1/4 wavelength or so for your mid-band 10 meter frequency... start with maximum vertical antenna length and slide the tubing into each other to get your lowest SWR. If your SWR goes up as you compress from maximum length, you need to lengthen one of the vertical tubes. Cheaper, faster. saves energy... LW --- In Repeater-Builder@ yahoogroups. com, "mark_n2mh" <[EMAIL PROTECTED]> wrote: > > Hello to the Group, > > Does anyone have any information or a cutting chart for the following > antenna? I have one and would like to put it into service on 10 > meters. It was given to me without any info or radials. It is > definitely used but appears to be intact. A quick web search turned up > nothing. > > Sticker Info on antenna: > > Antenna Specialists > Dallas TX 75247-6780 > ASPA 2010 > 30-40 MHz > 9209508 > Serial xxxxx-x > > It looks like a commercial version of a CB base antenna. The vertical > radiator is a series of telescoping aluminum tubing pieces held in > place with hose clamps. Maximum extended length of the vertical > element is approximately 21 feet. Minimum contracted length is > approximately 5 feet. The antenna uses 4 radials and the radial clamps > appear to accept 5/16 inch rods. (I'm not sure if the radials are > supposed to stick out straight or droop at some desired angle.) > > If nobody has any info, does the following tuneup procedure seem correct? > > 1. Cut a set of radials for 1/4 wL at 35 MHz. > 2. Adjust the vertical radiator for best SWR within 30-40 MHz. > 3. Measure and record vertical element, radial lengths, and frequency. > 4. Scale recorded dimensions to the desired 10 meter frequency. > > Thanks and 73, > Mark, N2MH >
