DMS Antennas & BYOR bench work meeting on Aug 13th

Interest Groups Amateur Radio
1

Let’s see how far we can get toward a workable antenna system and BYOR bench.

Since it’ll be hot outside, I’ve scheduled this for 8am on a Saturday.

https://calendar.dallasmakerspace.org/events/view/249

Hope to see y’all there!

73 DE N0ZGO

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2

Bump! Remember, we’ve got a work day coming up on Aug 13th. Any and all help from DMS members is welcome! Non-DMS members are welcome to observe our misguided attempts to run coax. :slight_smile:

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3

I have an old 10Mb network cable tester that will test cables for impedance bumps/issues and will tell you the feet to the fault.

Do you think that would be helpful for testing long lengths of coax that folks may want to bring in?

4

I don’t see why not, as it is a self-contained TDR (Time Domain Reflectometer).

Theory behind the TDR measurement.

Thanks!

5

I’ll try to make the event and bring it.

6

what coax are you running, lmr-400?

7

Based on the distance, that appears to be the leading candidate. We also plan to put a remote antenna coupler at the antenna on the roof to maximize the usable frequency range and minimize loss in the long run due to mismatch.

8

Reminder, Amateur Radio meeting/work day coming up THIS SATURDAY! We meet at 8am in the Electronics lab.

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9

8am?

I’ll be out with the wife in the morning hitting up estate sales. :frowning:

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10

Gotta pick your battles. :slight_smile:

11

Hello all. Due to the weather, we may not be able to get out on the roof, as planned, tomorrow.

However, we will still be working inside to map the coax run and benches, so join us for rainy-day indoor fun!

12

We had a great day for working on the roof yesterday: overcast but no rain or lightning. The existing dipole and VHF/UHF vertical is still upright! Total “tower” height is currently 18 feet off of the roof, but we’ve got another 10 foot section which can be added.

I paced off 135 feet from the existing tower to directly above the new BYOR bench in Electronics. If we have to use the existing penetration above Hatcher’s, we’ll need more than that to make the run due to vertical drops and zig-zag. Another option is to use an existing control cable egress for the HVAC RTU, and then run the cable straight across the roof to the tower. This would avoid having to do a lot of ceiling/fire-break work.

I’ve propose relocating the UHF/VHF antenna over by Electronics to minimize the cable run at the higher frequencies. Coax loss is pretty horrible as you leave the HF bands, without using some very expensive cable.

We have a new member who is willing to dedicate a multi-band dipole to the effort, which is greatly appreciated!

Plenty of room up there for a weather station (@Ebony_Jackson) and a remote SDR setup (@DanielHooper) .

Thank you to Walter (AF5WH), Andy (KE5KOF), Kevin (N5KRG), and Daniel.

Pictures to follow.

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13

I look forward to the next meeting!