View Single Post
Old 6-Apr-2020, 7:36 PM   #1
bobsgarage
Antenna Enthusiast
 
bobsgarage's Avatar
 
Join Date: Mar 2016
Location: Beach Park IL
Posts: 318
Extending a Stellar Labs 30-2476


Hi All,
Looking for some advice. This is a hobby project and it is my first attempt at modifying any antenna. If not successful, nothing ventured nothing gained...

A while back in 2011 a member on the help with reception forum made a post. He came back several years later, to follow up. "Wizwor" replaced his highly regarded Y10-7-13 with a modified 30-2476 with extensions of not one, but two front sections from two donor 30-2476's. His reception was much better than the original Y10.

http://forum.tvfool.com/showthread.php?t=2333

https://freetvforme.wordpress.com/20...b2#comment-921

So, I decided to take on a similar project. Amateur DXing. These are great VHF Hi antennas and relatively inexpensive and with the "Buy 4 discount" and another discount I got all 4 for $120, so I want to:

1) Extend the boom with another section and..
2) Build another the same and pair them by combining them using separate RCA PREAMP1R. Along with 2 Antenna Direct 91XG's See diagram :



I do my own Coax, so I'll be sure to make all cables the same length. I'll join them with a Holland Combiner after preamping with the RCAs. I like the RCAs because they double as a UVSJ.

I did some measurements and the directors taper smaller and smaller to the front of the stock antennas. So, I have some front sections from the two donor antennas but the rearmost directors would be wider than the front most directors on the two base antennas.
I have a diagram:

So, here's what I've got so far:



Factory stock:




Extended:



Here's the boom spacing, I could close the Distance about 4" by putting the Antenna to the inside of the "U" which is 1 3/8 " aluminized exhaust tube.:




Here's how I imagined rearranging the directors:



So I looked at some Antenna modeling software but it's too intimidating to be sure. That's why I'm here for advice. Tom Ballister used a signal spectrum analyzer to modify his Y10 7-13. I wished he have done the 30-2476, I would just copy his design!

Here's a list of my current questions.

a) What should the director spacing be?

b) What can I use to join the donor section?, there will be a gap and I can't find the right size square box tubing to sleeve the boom on the outside or inside. .655" ID .710" OD or 16.350 ID 18mm OD

c ) Vertical stack or side by side? With either, what should the spacing be?

d) Will the "u" between the booms disrupt the signal if it's below the reflector?

e) Should I use any of the rear section? Directors etc...

Subquestion, why do the Y10 7-13 have two dipoles? since I have extra dipoles could they be used somehow?


Now, I have two complete rear sections left over, Dipole, directors and baluns, 2 of each, should I be using any parts off of those?:



Attached Images
File Type: jpg received_1296644304057213.jpg (34.1 KB, 3224 views)
File Type: jpg 20200404_172847.jpg (91.1 KB, 3136 views)
File Type: jpg 20200403_170103.jpg (357.6 KB, 3200 views)
File Type: jpg 20200403_190521.jpg (202.0 KB, 3192 views)
File Type: jpg 20200403_171331.jpg (94.1 KB, 3147 views)
File Type: jpg 20200404_170257.jpg (209.8 KB, 3031 views)
File Type: jpg 20200406_141817.jpg (98.2 KB, 3263 views)

Last edited by bobsgarage; 23-Oct-2020 at 8:18 PM.
bobsgarage is offline   Reply With Quote