It would be fun to get a meter on the 5/8 wave Larsen @440 and see what it looks like officially. I split time almost equally between 2m and 440 so need something for both that I don't have to worry about. I use 6 and 10 less frequently, but enough to want something that works.

Good suggestion, but that leaves me without a 10m solution.

Yeah, thanks for that constructive contribution.

I'm currently running the EX-510 and I'm trying to move away from it because, contrary to your experience and everything I read I can't get an acceptable SWR if the antenna is grounded! I checked using a different 2/440 antenna to rule out the rest of the install and all is well. But if I insulate the mount from ground the Maldol is happy 1.3:1 or better which is how I've been running it prior to getting the 10m antenna. When I add the Larsen 27 (that needs a good ground and the duplexer) the Maldol SWR goes to 4:1 and up on 2 and 6. Hence the thought exercise presented..

IMHO The only time Microsoft will make a product that doesn't suck is when they try their hand at making vacuum cleaners.

I'm pretty sure I know the answer to this one, but I'm gonna ask it anyway (Flame On!).

Lets say I want to run the Larsen 150 5/8ths wave with my FT8900 to cover 2m and 6m (@K0BG: I know, I know, the 6m match would be a compromise, I just want to be able to hit the local 6m fm repeater.. for the sake of the thought exercise stay with me). What would that look like on 70cm? I assume it won't work but am hoping to be proven wrong.

If I'm right my next question is: Is there a 5/8ths wave on 2m / 440 dual band antenna out there? I'm pretty sure the Larsen 2/70  is a half wave and will not work as a 6m 1/4 wave so what other options might there be.

I have considered a duplexer and a dedicated 440 antenna, but this would put 3 antennas and 2 duplexers in the mix. (I currently use a CF-360 to split the Larsen 27 nmo cut for 10m away from a 6/2/440 triband that I'm only marginally pleased with)

Thanks!

73

Dave

That is my next step I ran out of time last night (with 2 small kids, radio time can be scarce) ;-)

Hi all I'm investigating a sudden increase in swr and am suspecting the comet cf-360 duplexer. I use it to split 10m to my Larsen 27nmo antenna cut for 10m fm, and divert 6m, 2m and 440 to the Maldol Ex510b.

Running the individual antennas directly to the ft8900 yields acceptable swr. (External meter) Through the cf-360, swr increases on 10m slightly, but jumps up from 1:1.5 to over 4 on 2 meters.

I did a continuity check and the hf side shows center to center continuity, and shield to shield continuity. The 6m-440 side however is not showing continuity through the center pins. I'm not sure if this is expected behavior through the duplexer or if this is telling me the smoke got out.

Any thoughts on what to check next?

Thanks!

73

Dave

Did you throw your call out? I've found that seemingly "dead" repeaters often have folks listening that are for whatever reason to shy to initiate a QSO.


73
KJ4OBR

Or She will banish you to the couch for messing with her car. Good luck w/ that! ;-D

Try http://www.vanityhq.com/ on the menu on the left there is a ham locator.

73
Dave

Glad to help.

73
Dave

The only devices that really care are Apple products. Apple has "extended" the USB connection to "protect" their stuff. (Read "force you to by replacement chargers from Apple") from what I understand they have a series of resistors on the data lines that feed voltage into the data line that the Ipod/Ipad measures to decide if it can charge and at what rate.

The protection has of course been reverse engineered. You can read more here http://www.ladyada.net/make/mintyboost/icharge.html

I use a 12v to USB 5V to feed my APRS GPS receiver, works like a charm.

73

Dave

I've drilled and re-tapped an antennex trunk mount and didn't have an issue. If it fits over the lip of a trunk he should have enough space to get the small tap through. If not, get a cheap tap at harbor freight and grind the point off and finish the process with the modified tap. Still less cost, damage, and hassle then trying to heat it.

73
Dave

I'd still drill and retap. Maybe an hours worth of work (if you take a beverage break)   The set screws are not tempered and are actually pretty soft metal (which is why they seem to strip so quickly even without locktite).

I would worry about changing the temper of the mount material by heating. Plus the heat is going to do a number on the powdercoat/ paint of the mount.

By the time you run around and get everything you need to heat it, do the job, and fix the damage, you could have ordered a new mount from Hong Kong, had it shipped by rowboat and installed on the other car.

73
Dave