As I recall the Z3801 documentation it specified a
certain level of cable attenuation being acceptable,
since the antennas themselves are amplified. Don't
have access to that information right now though. But
I'm sure that the collection of adapters, including
SO239/PL259's (a really BIG ouch at ~1.6Ghz) is doing
you in. My off the cuff guess would be that single run
of LMR400/9913F or equivalent with proper N connectors
will solve your problems.
Duane
N9DG
--- Mark Erbaugh <mark@microenh.com> wrote:
> I received my HP Z3801 last week. To keep things on
> topic, the intent is to
> use it as an external reference for my RX340.
>
> I mounted the antenna over the edge of my garage
> roof. That was the easiest
> place to get a good view of the sky. If I try to get
> closer to the shack, I
> will have to find someone to climb on my two story
> roof. The supplied lead
> in barely made it to the ground. I took the clock
> outside and hooked it up
> directly to the end of the antenna. Using my laptop,
> I verified that all was
> good. It was able to track 5 or 6 satellites and
> successfully completed the
> survey operation (took about 3 hours).
>
> However, I really want to install the clock in the
> shack. That's going to
> take another 30 - 35 feet of cable. I took some
> spare coax jumpers and
> adapters and brought the signal into the shack, but
> the clock wasn't able to
> receive any satellites. I suspect that with all the
> adapters more coax than
> the minimum length, I just had too much attenuation.
> Also, I had checked the
> jumpers out for HF or 2m operation (RG-58).
>
> Here was the arrangement
>
> supplied lead in cable terminating in BNC - BNC /
> PL259 adapter - SO239
> barrell connnector - 50 - 60 feet of RG58 with PL259
> fittings on each end -
> SO239 bulkhead fitting (to go through wall) - 25
> feet of RG58 with PL259 on
> one end and BNC on the other - BNC to N adapter
> (supplied w/ antenna ) -
> clock..
>
> Anyways, my question, what's the best way to go
> about extending the GPS
> antenna. Since we are talking about 35 feet, I'm not
> adverse to buying some
> more expensive coax to reduce line loss. I'll also
> go directly through the
> wall with coax and skip the bulkhead fitting. I'd
> also put the N fitting
> directly on the clock end of the cable. For
> connecting to the existing
> antenna, should I cut of the existing BNC and
> directly splice the new
> feedline (and how would that be done?), or would it
> be better to try and
> install a matching BNC fitting and connect to the
> BNC already there?
>
> Or is this a lost cause and do I need to figure out
> to get the antenna
> closer to the shack?
>
> 73,
> Mark
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