Hello Andrew and Norm
If you are trying to figure out the lengths needed for 144-148Mhz I can
measure what you need to know but not in a hurry. I have a DB products antenna
that is cut for the two meter band that I ordered from DB Products about 10
years ago. What I need to know is the measurements for 220Mhz. I also have
several DB224a's that have been removed due to problems. These could easily be
modified to cover 220Mhz. 73 de Tom Manning, AF4UG
----- Original Message -----
From: NORM KNAPP
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, February 17, 2010 10:35 PM
Subject: RE: [Repeater-Builder] DB224A new harness
The unknown coax type is/was VB-83 (35 ohm). The VB-8 is of course 50 ohm and
the VB-11 is 75 ohm.
I hope that is the info you needed. It would be great if you could figure out
what the open stub is for and can we use that for adjustments. If you need more
info, let me know.
73
Norm
________________________________
From: Repeater-Builder@yahoogroups.com on behalf of allan crites
Sent: Wed 2/17/2010 9:29 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] DB224A new harness
I tried to work backwards on a Smith Chart from the dipole to the 1/2 WL O.C.
stub to determine a reason for the stub but it appears the unknown coax types
are causing erroneous and confusing answers.
Can you confirm the coax types shown on your diagram?
a.
--- On Wed, 2/17/10, NORM KNAPP <nkn...@twowayradio.net> wrote:
From: NORM KNAPP <nkn...@twowayradio.net>
Subject: RE: [Repeater-Builder] DB224A new harness
To: Repeater-Builder@yahoogroups.com
Date: Wednesday, February 17, 2010, 3:57 PM
I got the harnesses at no charge from Andrew. I contacted customer support
and told them I had 3 fairly new DB224's (2 a models and a b model) that had
water intrusion/contamina tion in the harness where they were supposedly seal
by the factory. I offered pictures and they accepted. Upon seeing the photos
they asked that I give them serial numbers and requested I send the defective
harnesses to them. I did and they offered and I accepted replacement harnesses.
The two db224's that I have (personally) are the A models. The B model
belongs to my shop. I often end up with abandoned and or defective db224's and
other antennas as I work for a two way land mobile dealer/shop. Unfortunately,
I have yet to get any DB224e's or any DB304's, just tons of DB224a's and an
occasional DB224b.
Hats off to Andrew for shipping me free replacement harnesses. I am still
gonna ScotchKote those moldings regaurdelss.
If you look at the attached photoes from my initial post, you will see that
the open 25" VB-8 (50 ohm) stub is 12.5" from the "T" where the top half and
bottom halves of the harness come together, down the main feed to the hardline
(or whatever you feed the antenna with).
Last night I connected the Sitemaster up again and I noticed the the SWR will
come down some when I firmly secure the harness to the mast with the metal
tape. How far down remains to be seen. I will keep you posted.
73 and thanks!
de N5NPO
Norm
