[time-nuts] Troubleshooting an HP 58503A

Tom Miller tmiller11147 at verizon.net
Sun Oct 14 19:42:30 EDT 2018

----- Original Message ----- 
From: "jimlux" <jimlux at earthlink.net>
To: <time-nuts at lists.febo.com>
Sent: Sunday, October 14, 2018 7:07 PM
Subject: Re: [time-nuts] Troubleshooting an HP 58503A

> On 10/14/18 3:03 PM, Matthew D'Asaro wrote:
>> All -
>>  Thanks again for all the suggestions and advice I have gotten on this 
>> project. It ran all night without loosing lock, so I am calling it fixed. 
>> There is just one more order of business before I can use it, and that is 
>> some way of "mounting" the GPS antenna on the roof in a non-destructive 
>> manner, both to avoid damaging the (flat membrane) roof and so that I can 
>> move it if necessary. See the attached photo of what I have come up with. 
>> All the parts (minus the cable and antenna) came from Home Depot.
>>  The concrete block is a generic 1 sqft paver stone which cost all of 
>> $1.18. This is to provide a heavy base and avoid tipping. Attached to 
>> that is an upside-down PVC toilet flange from the plumbing section. It is 
>> attached with 6x stainless steel machine screws and wing-nuts that pass 
>> all the way through the paver and are counter-sunk on the bottom so that 
>> the heads won't damage the roof. Nylon spacers separate the toilet flange 
>> and paver block by about 1/4 inch so that water can drain if needed and 
>> to provide a space for the coax feed line to come out. Pressed into the 
>> top of the paver is a 3" to 2" reducing adapter and pressed into that is 
>> a 2" to 1-1/4" reducing adapter. The mast itself is just a 2-foot section 
>> of 1-1/4" PVC pipe. The 58532A antenna is apparently designed to mount 
>> over a 1-1/4" mast since its inner diameter is 43mm and the outside of a 
>> 1-1/4" pipe is 42mm.
> Standard "non-penetrating" roof mounts use this technique - they have a 
> frame which you ballast, by bricks, pavers, or sacks of gravel.
> After that it's more a matter of figuring out how to do the mechanical 
> structure - sandbags and plumbing fittings are a fine way to cobble 
> something to together.

Don't forget to place a rubber pad under the paver to protect the roof 


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