Also keep in mind the application. On a repeater antenna, 3 dB could be a deal-breaker. On a link, it might be well worth the tradeoff.
Resistive losses also lower Q, which increases SWR bandwidth. If you have a remote base, there may be times when introducing a little loss to gain bandwidth might even be desireable. The military, where efficiency is not a design requirement, has taken this to extremes at times. One WWII-era "broadband HF whip" used on Army vehicles was an 8-foot whip on a 1 kW dummy resistor. Extremely crude, but it worked! 73, Paul, AE4KR ----- Original Message ----- From: [EMAIL PROTECTED] To: [email protected] Sent: Sunday, May 04, 2008 10:29 AM Subject: Re: [Repeater-Builder] Re: antenna question - Dip It and Scotch Kote The problem with high loss tangent is that you'd never see it as reflected power. You could lose 3 dB or more & never know it. Bob NO6B At 5/4/2008 04:53, you wrote: >Boy, you took a gamble. I'd have been afraid that this action could have >either messed up the VSWR or shifted the resonant point of the antenna. Then >again, maybe it did and either you don't know that or it wasn't significant. > >Chuck >WB2EDV > >----- Original Message ----- >From: "skipp025" <<mailto:skipp025%40yahoo.com>[EMAIL PROTECTED]> >To: ><<mailto:Repeater-Builder%40yahoogroups.com>[email protected]> >Sent: Sunday, May 04, 2008 12:19 AM >Subject: [Repeater-Builder] Re: antenna question - Dip It and Scotch Kote > > > Hi Robert, > > > > You might get lucky... because they might also have advertised > > the dip-it as an insulator material, which means someone was > > hopefully looking at the dissipation factor (aka D-Factor) when > > the compound was engineered. Time will tell... > > > > cheers, > > skipp > > > >> "georgiaskywarn" <[EMAIL PROTECTED]> wrote: > >> Someone else told me that after I had put a whole can of dip > >> it on the db408 I showed you. I went back and covered every > >> inch of it with liquid electrical tape. I have had good > >> results in the GA sun with it. > >> 73, > >> Robert > >> KD4YDC
