Is the G5RV wire dipole antenna a very good multi-band HF antenna?

Bottom line is no, it’s not. 

The designer Louis Varney G5RV designed this antenna as a 20 meter resonate dipole. Unfortunately the G5RV has been mislabeled as a efficient effective multi-band wire dipole which it is not. The extreme mismatch when used on other bands with a transmatch, in conjunction when using coaxial cable cause the power loss to be out of site. A misuse of the original design.

Recent marketing ploys of the G5RV Jr and G5RV Sr are laughable at best. A perfect marketing strategy aimed at the lazy ham looking for the easy way out, instead of the better way that requires more effort. 

Little do these uninformed amateurs realize by simply removing the lossy coaxial cable, and replacing it with a non resonate length of open wire, then extending the dipole length from 102 ft to 135 ft, or 270 ft, the effectiveness and efficiency greatly increase. 

Those administering amateur radio test, should know the rules better than the typical amateur..

Unfortunately many do not.

You are not required to announce your call-sign when you begin a transmission, nor are you required to announce your call-sign at 10 minute intervals.

If you choose to announce your call when you begin a transmission, and watch a clock so you ID each ten minutes, more power to you. However chastising those on-air who are operating within Part 97, makes you look like a fool.

§ 97.119  Station identification.

(a) Each amateur station, except a  space stationor  telecommand station, must transmit its assigned call sign on its transmitting channel at the end of each communication, and at least every 10 minutes during a communication, for the purpose of clearly making the source of the transmissions from the  station known to those receiving the transmissions. No  station may transmit unidentified communications or signals, or transmit as the  station call sign, any call sign not authorized to the  station.

(b) The call sign must be transmitted with an emission authorized for the transmitting channel in one of the following ways:

(1) By a CW emission. When keyed by an automatic device used only for identification, the speed must not exceed 20 words per minute;

(2) By a phone emission in the English language. Use of a phonetic alphabet as an aid for correct  station identification is encouraged;

(3) By a RTTY emission using a specified digital code when all or part of the communications are transmitted by a  RTTY or data emission;

(4) By an image emission conforming to the applicable transmission standards, either color or monochrome, of § 73.682(a) of the  FCCRules when all or part of the communications are transmitted in the same  image emission

(c) One or more indicators may be included with the call sign. Each  indicator must be separated from the call sign by the slant mark (/) or by any suitable word that denotes the slant mark. If an indicator is self-assigned, it must be included before, after, or both before and after, the call sign. No self-assigned  indicator may conflict with any other  indicator specified by the  FCC Rules or with any prefix assigned to another country. 

(d) When transmitting in conjunction with an event of special significance, a station may substitute for its assigned call sign a special event call sign as shown for that  station for that period of time on the common  data base coordinated, maintained and disseminated by the special event call sign  data base coordinators. Additionally, the  station must transmit its assigned call sign at least once per hour during such transmissions. 

(e) When the operator license class held by the control operator exceeds that of the  stationlicensee, an  indicator consisting of the call sign assigned to the  control operator‘s  station must be included after the call sign.

(f) When the control operator is a person who is exercising the rights and privileges authorized by § 97.9(b) of this part, an  indicator must be included after the call sign as follows:

(1) For a control operator who has requested a license modification from Novice Class to Technical Class: KT;

(2) For a control operator who has requested a license modification from Novice or Technician to General Class: AG;

(3) For a control operator who has requested a license modification from Novice, Technician, General, or Advanced Class to Amateur Extra Class: AE.

(g) When the station is transmitting under the authority of § 97.107 of this part, an  indicatorconsisting of the appropriate letter-numeral designating the  station location must be included before the call sign that was issued to the  stationby the country granting the license. For an amateur service license granted by the Government of Canada, however, the  indicatormust be included after the call sign. At least once during each intercommunication, the identification announcement must include the geographical location as nearly as possible by city and  state, commonwealth or possession.[54 FR 25857, June 20, 1989, as amended at 54 FR 39535, Sept. 27, 1989; 55 FR 30457, July 26, 1990; 56 FR 28, Jan. 2, 1991; 62 FR 17567, Apr. 10, 1997; 63 FR 68980, Dec. 14, 1998; 64 FR 51471, Sept. 23, 1999; 66 FR 20752, Apr. 25, 2001; 75 FR 78171, Dec. 15, 2010]