[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

RE: Icom 706

Ok, how bout the ultimate?  Anyone got an all mode 2m rig they wanna sell


On Fri, 24 Mar 2000, Tony Langdon wrote:

> > Ok, here's a thought.  My principal reason for wanting the 
> > smaller rig is
> > for travel.  That said, it's looking like I will go with the 
> > 706 for now.
> OK, cool. :-)
> > 
> > Now...  With all the fuss about the full duplex issue...  I 
> > own several 2M
> > FM rigs.  My primary interest is in the AO27 bird and working the FM
> > Repeator type birds.  I can do this effectively with the 
> > 706's 70cm side
> > (Which has a hell of a lot better tuning than my HT) and a 2M 
> > Mobile rig.
> This will work well, and in a mobile situation, the lack of full duplex
> isn't as big an issue as it is with portable operation or when using SSB.
> > Is *THIS* a solution that will keep me out of the Wolfhong 
> > (SP?) hall of
> > fame with you guys??
> > 
> > SInce my other interests are in HF, VHf Terrestrial, I think this is a
> > good solution.
> > 
> > I may regret this.. But, Comments??
> I may offer a little experience here, through operating on SO-35 and UO-14
> (i.e. the 2 FM birds we get down here).  Personally, I find full duplex
> serves two purposes.  Firstly, it's an instant check on one's signal
> quality.  For you, this is really a minor issue.  Secondly, and related to
> this is where you're able to adjust power or, especially antenna
> orientatation, the ability to monitor your own signal allows you to adjust
> for the link characteristics in real time.  Again, for a mobile, this isn't
> as big an issue, as you can't easily pick up the car and wave the antenna
> around (:-) ).  For portable operation, like I usually work, this ability is
> the difference between success and failure, due to the smaller fade margins
> you have when running limited power (in practice it makes the difference
> between getting a good signal on a fraction of a watt and barely accessing
> the bird on 5 watts when portable).
> There are two other practical issues, again they won't stop you working the
> birds, just means you're flying a little "blind", compared to the rest of
> us.  Firstly, you won't know if you've been clobbered in a dogpile (or by an
> alligator).  But that's a bit similar to being in the thick of a contest
> pileup, except most others will know the outcome!).  Secondly, if the bird
> is quiet, you may have no means of knowing if you can hear the downlink (as
> they Tx noise when there is no signal on the input).  This is less of an
> issue in the US, as you guys have much higher traffic levels.  Down here,
> you may not know if you ever heard it during a late pass.  With full duplex,
> you'll know as soon as you hit the button (and if you can't hear yourself,
> will know not to Tx too much!).  Suffice to say, you feel 'blind' running
> half duplex when you're used to full duplex. :-)
> In short, I think the 706 will be fine for the FM birds, with a small amount
> of compromise.  For SSB/CW operation, it would be extremely difficult, as
> you won't be able to monitor your own Doppler shift (which you can guess to
> "near enough" for FM :) ).
> Anyway, that's my 2 cents worth. 

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org