[Rover] Interstation Interference in Multi-Op Rovers

[Robin Midgett]

I also have short sections of 7/8" & 1-5/8" available.

On Fri, Sep 22, 2017 at 1:47 PM, Robin Midgett <K4IDC at comcast.net> wrote:

> I have scads of CATV hard line. I'm happy to cut a section & send it to
> you. 1/2", 3/4" & 1" diameters.
>
> On Fri, Sep 22, 2017 at 1:38 PM, Sean Waite <waisean at gmail.com> wrote:
>
>> Hi Jonesy,
>>
>> I don't know why my brain stuck on blocking the 6m signal at the 2m radio.
>> It makes much more sense to do block the ~150MHz harmonic at the 6m radio.
>> Any idea how much difference a lower Q piece of coax - either thinner
>> heliax or something like LMR400 - would change the results? I gather it
>> makes them a little more broadband, but I don't know for sure. CATV cable
>> is great but can be a little hard to get a hold of.
>>
>> We were getting some minor interference on  432 as well. I might have to
>> look into a stub there as well.
>>
>> Thanks,
>> Sean WA1TE
>>
>> On Thu, Sep 21, 2017 at 9:21 PM Jonesy W3DHJ <mailserver at jonz.net> wrote:
>>
>> > On Thu, 21 Sep 2017, Sean Waite wrote:
>> >
>> > >Thanks, I suspected it might be something like that. We get some
>> lighter
>> > >interference on 70cn as well, which is a few more harmonics up.
>> > >
>> > >My worry with the coax notch filters is bandwidth - 150MHz is pretty
>> close
>> > >to 2m. I suppose using higher quality coax/heliax and tuning to 51MHz
>> > would
>> > >help with that.
>> > >
>> > >The rigidity of heliax might make it rough in the rover, a 5' long
>> chunk
>> > is
>> > >going to be interesting g to manage and will likely go somewhere
>> outside
>> > >the car on the ground.
>> >
>> > Use 3/4" cable TV "hardline" -- use it as a 144.2 mcs suck-out trap on
>> > the 6M rig -- an open 1/4 wave at ~~15" or a shorted 1/2 wave at ~~32".
>> >
>> >                 https://w3dhj.net/catvhardline.html
>> >
>> > If you try to trap the 6M rig (50.130 mcs) at the 2M rig, you run into
>> > the problem of the 6M trap working just as nicely at 150.39 mcs -- which
>> > may be too close, Q-wise, for the 2M rig.
>> >
>> > Another issue - besides just "interference" - is the possibility of
>> > blowing out the front end of the 2M receiver with simply the
>> > overpowering by the 6M rig.  I blew out a 2M GasFET preamp because
>> > my 6M halo is mounted between my stacked pair of 2M halos.
>> > Sigh...  I just do without that GasFET preamp now.
>> > I can certainly hear anyone that can hear me!  HI!HI!
>> >
>> > Jonesy
>> > --
>> >   Marvin L Jones     | W3DHJ      | W3DHJ  | https://W3DHJ.net/
>> >    Pueblo, Colorado  |  @         | Jonesy |     __
>> >     38.238N 104.547W |   jonz.net | DM78rf | 73  SK
>> >
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>
>