In response to all queries:
The Comet NMO antenna has only ever been screwed onto Antenex NMO mounts...I used the same mount thru the truck roof that I used thru the car trunk lid....and that installation works excellently...beyond just good.  So I would think that the antenna center pin would make contact equally well (or equally poorly) on each vehicle.
I used the Antenex NMO mount hole saw that they sell to make the 3/4" hole for the antenna so the paint on the outside (I went down from the top so the rough edges would be on the inside where the o-ring wouldn't have to seal) should be scuffed properly.
I think the plan here is going to be to loosen the mount enough to be able to make sure that the two "claws" on the back of the mount make contact with bare metal.  Then we'll try it again.  I think I don't have an open at the center connector...both mounts are the exact same Antenex part.  We'll see how that works.
Thanks to all for the helpful advice.

Well, I'm not so sure that I'd say I was playing the gain game...those just happened to be the two antennas I had on hand and I was trying to figure out why a better mount gave me poorer performance....I didn't buy them based on their gain figures....I've had that SO-239 Diamond for years.  I hope I don't screw up the o-ring by unscrewing the mount enough to sand through the paint on the back side...I tested the mount with a strong spray of water with no leaks right after I installed it...I don't want to lose that water-tightness by jacking around with it further.
If the Comet was not making contact with the center conductor would not the radio have folded back?  I saw no evidence of that on the transmitted power meter.

I used Antenex.  I didn't specifically do anything to the paint on the back...does anyone know of a way to unscrew the mount without trashing the one and only rubber o-ring under the top brass collar so I can open things up and scrape the paint on the back?
I used the Comet on the car because it's tri-band..the idea was I could hook it to the 220 HT if need be.  It has always performed excellently on the car.  I used it temporarily since I didn't have any other NMO antenna at the time I installed the mount yesterday.  I'm getting away from that idea since I very rarely use the HT in that way...there's not enough 220 to make it worthwhile.
So do you think the Diamond worked better because of it's "gain" or because the NMo mount had a poor ground?
Thanks.  KB9WQJ Mike

Hello all,

I was wondering if anyone can shed some light on this.  I have a Ford Expedition...for years I have had a lip-mount antenna on the back hatch...a Diamond SG7900A on an SO239 mount...stated gain on 2m is 5.0 dBi.  I recently, because everyone is so adamant that the ground plane is better and it's a better mount, etc, etc, etc) installed an NMO mount right on the roof of the SUV.  I moved an antenna that I already had on my car onto this mount to try it out.  That antenna is a Comet SBB224...stated gain on 2m is 2.15dBi.  There is a repeater that I don't consider too far away...I was able to use this repeater with the old antenna setup and the received signal is about S5-7 on the S-meter of my 706 MkIIG.  When using the new roof mount with the Comet I was unable to raise that repeater at all.  Since everyone knows that NMO mounts in the middle of the roof are the best, and everyone also knows that gain figures in antenna literature are bogus...why was the performance so much poorer?  Or since the RELATIVE gains are so much different that accounts for the difference?  Please advise.  Seems like I did some work for a net negative in performance?
Thanks, KB9WQJ Mike

 Hello folks...lest you think I'm not doing my due diligence here, I have read much at K0BG.com and done a search here on MobileHam Forum and read the threads that look like they might apply but I was unable to find the answer to my question.  Google was also no help.

  I'm giving up the mag mount and going to drill a hole in the trunk of my 2005 Ford Focus.  I'm not doing the roof due to the fact that the headliner looks hard to remove or replace and removing the dome light assembly structure doesn't look like it goes far enough towards the back of the vehicle to clear the slanting broadcast antenna that's mounted at the front of the roof and slopes back towards the rear.  Ruinning the coax is easier from the trunk..I know since I've already done it for the mag mount I'm replacing.

  My question regards actually drilling the hole...I have purchased (and it's not here yet) a standard 3/4" NMO from Antenex as well as the Antenex HS34 antenna hole saw.

  Since I've never done this before...does it matter which side I drill the hole from?...ie. from the outside (downwards) or from the inside (upwards).  I want to do this right since you always see everyone say that "a properly installed NMO does not leak" which must mean that improperly installed ones do leak.  I also want to make sure that nothing rusts and I understand that the Antenex hole saw scores the paint around the hole for the proper ground plane....wouldn't such scoring be better off on the inside away from the elements?

  Thoughts?

  Thanks in advance.  73 de Mike

Don't worry about giving out number 4.  I did only 4 contacts Saturday during the contest...I was testing an antenna setup for portable (read: camping) use and only had an hour or so total to mess with it.  One of my contacts was Madiera Island so I'm relatively pleased.  I also turned in my log to the contest sponsor as a checklog so the 4 stations I talked to wouldn't get dinged for uniques...which is something I always do at the very least if I work stations in a contest.  Contests can be useful for advancing your own goals such as testing something out or advancing your DX totals, etc.

73 de Mike

Replace it with a sheet of metal instead and when you use bulkhead-type polyphasers on it you only have to run one ground from the metal pane to ground.
73 de Mike

Ah, didn't think of where they are.  That makes sense having just been through our own "ain't got no power for about a week" event here in the Metro East of St. Louis.  That's probably it.

   Is anyone else having trouble getting to www.icomamerica.com ??  I was going to DL a new band chart (not saying anything about it...but just wanted a reference) and I haven't been able to bring up their site since Friday.

Haven't tried that (dummy load).  May try that when the rig gets back.  I was finally allowed to talk to the senior tech today...he said he can only duplicate the symptom with a low voltage.  So I need to troubleshoot my power installation.  Maybe a loose connector.  I did run 10ga all the way to the battery both sides.  I'm going to run some voltage tests also.
Thanks.

  I have a new Yaesu FT7800R.  I'm told that upon the first few seconds of some (but not all) transmissions there is a squealing noise almost covering up my voice.  It stops after a second or two and the rest of the transmission is fine.  I cannot seem to trace it down to when the rig is hot or cold or just turned on or has been on for hours.  It is powered using 10 ga red/black directly to the battery fused both sides just as Yaesu indicates in the manual.

  I sent it to yaesu under warranty for repair.  They have had it for 5 weeks now and several techs have looked at it.  Now it is in the hands of a "senior tech".  No one at Yaesu can find anything wrong with this radio.  I even sent so far as to send them a CD with a recording of one of my transmissions made from my home station that clearly has the noise present.  I made this recording so I could hear for myself what my friends were telling me.

  Yaesu wants to send the rig back to me unrepaired.  I think that if my radio is in such excellent shape that they cannot find anything wrong with it then I should be sent a new radio if they can't repair mine.

  In any case, does anyone have any ideas as to what might be causing this so that I can give the senior repair tech some avenues to explore?  The only thing I can think of is that the voltage may be dropping right at the beginning of a transmission but what would cause that since the power wiring should be adequate to the task as should the battery and charging system of the vehicle.  I'd really like my new rig back...I've already forgotten the menu system that I was starting to learn when I sent it back to them.

  Any ideas?  Thanks.

Hospital pharmacist here...you're looking for tincture of benzoin...it's not an adhesive per se...but it assists other adhesives like those on bandage tape.  Not sure if it's available OTC....it doesn't see much use anymore...it's an OLD thing.
73

When I get a chance (hopefully tonight when I get home but maybe not)I'll look and see...I have the Degen version not a Kaito so I may have the Chinglish one.  Are you in much of a hurry?  If I have it I'll scan it and email it.  Let me know if the Degen one would be worthwhile.
73 de Mike

I'm currently using a Nite-Ize case...works fine even with the Kenwood metal belt clip still installed.

It does turn off the radio.  I leave mine off unless I'm actually using it in a wireless manner.  I usually run the two house computers from Ethernet cables and rarely bring the laptop home from work.  If I do, I turn it on at that time.