Thanks to all for the info I needed on these antennas. With the nice weather around here, I have some projects to do. I have a few questions though... The 4 bay antenna is shorter than the 2 meter version, so I think I will need to lengthen it a bit. How should I secure the new metal to the old metal? How would I "tune" each element? All I have for equipment is an MFJ antenna anylizer. I haven't checked the harness yet, so if I need to change it, what kind of coax do I use? Can I use connectors and tee to make the new harness? I have built beam antennas, but this is a new area to me. Thanks for the advice. 73 Mike - N7ZEF
----- Original Message ----- From: "skipp025" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Tuesday, February 28, 2006 10:18 AM Subject: [Repeater-Builder] Re: Antenna advice Let me see if I can help with the DB Antenna, which from the size reads like something for the VHF Range. We've done the work for you... go to the repeater builder web page www.repeater-builder.com and look at the Decibel Antenna drawings that others and myself have provided. The VHF Antennas from 138-174MHz were made in three or four models that covered smaller portions (band segements) within the above listed frequency range. You'll see something like DB-224A, DB-224B and DB-224C as examples of them mentioned. You'd first want to ID what model you have and then figure out if it would work for your needs. The various models do go out of band a bit, but I've not found the VHF antennas to be as usable out of band as the UHF versions seem to be. The physical size of the dipole is the better indicator of where the antenna operates (band segment). If the DB Ant is another 160 MHz model ... I would say it's not going to be easy to mod and use it for 146MHz (2 meter) operation. If you look at the DB Antenna drawings we've provided, you'll notice the physical size of the Dipole Elements change quite a bit when moving from the 138-150 segment vhf antenna up to the 150-162 segment (frequecies ranges may not be the exact values, used for the example only). The coax harness also changes for the band segments. I've found it not so easy to get a 150-160MHz and higher band segement to work well down into the ham band. Since the dipole elements change size at the 150 MHz "breakpoint" it's not really easy to (increase the size of...) resize/mod the Dipoles Elements without major metal work. You then have to make/copy or buy a replacement coax harness for the lower band segment once you rework the Dipole sizes . Life goes on... hope that helps a bit. cheers, skipp > "n7zef" <[EMAIL PROTECTED]> wrote: > > I was recently given 2 antennas, and I need to know if they could be useful > for 2 meters or in the scrap yard. > > One is a Sinclair 2 bay antenna Model # SRL210C2HD*2. Sticker on it says > the frequency os 160.860. > > The other is unknown. It is a 4 bay antenna with just the elements and > phasing harness, no boom. Each element measures 34 in total length OD, 2.75 > in width OD, 1/2 inch dia tubing. The wording stamped in the phasing harness > says D.B. Products. > > Like I said, I would like to know if these could be made to work on 2 > meters... > > 73 > Mike - N7ZEF > Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
