I got an Yagi 5 element vhf antenna, and I don't know how to calculate the anteenas frequency cause antenna based on 2 dipoles (trombone and reflector) that means that the reflector phase is 90 degrees.
Thanx
Yagi Frequency
Moderator: Queue Moderator
Yagi Frequency
Hi guys,
I got an Yagi 5 element vhf antenna, and I don't know how to calculate the anteenas frequency cause antenna based on 2 dipoles (trombone and reflector) that means that the reflector phase is 90 degrees.
Thanx
I got an Yagi 5 element vhf antenna, and I don't know how to calculate the anteenas frequency cause antenna based on 2 dipoles (trombone and reflector) that means that the reflector phase is 90 degrees.
Thanx
-
Tom in D.C.
- Posts: 3859
- Joined: Tue Sep 04, 2001 4:00 pm
- What radios do you own?: Progreso soup can with CRT
Antenna frequency...
Looks to me as if the 80.5 cm element is at 177 mHz.
(80.5cm/2.54cm to the inch =31.7 inches)/12 in. to the
foot=2.65 feet.
468/177mHz=2.6440677 feet for a halfwave at this
frequency.
You can do the math for the longer element by changing
the 80.5 to the longer dimension.
How they interact I don't know.
(80.5cm/2.54cm to the inch =31.7 inches)/12 in. to the
foot=2.65 feet.
468/177mHz=2.6440677 feet for a halfwave at this
frequency.
You can do the math for the longer element by changing
the 80.5 to the longer dimension.
How they interact I don't know.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
I think that 177MHz it's impossible its not commercial.
I have tried to do the same calculations.
Some history:
This antenna manufactured before 15-20 years and it was connected to repeater at Eilat city in Israel. As I know at theese years the most popular frequencies were 136-144 Mhz @25 kHz bandwidth.
Other option that antenna is for UHF... I will check it....
Thank you very much for the information!
Maybe some one have the datasheet for this model ???...
I have tried to do the same calculations.
Some history:
This antenna manufactured before 15-20 years and it was connected to repeater at Eilat city in Israel. As I know at theese years the most popular frequencies were 136-144 Mhz @25 kHz bandwidth.
Other option that antenna is for UHF... I will check it....
Thank you very much for the information!
Maybe some one have the datasheet for this model ???...
-
440roadrunner
- Posts: 236
- Joined: Mon Aug 16, 2004 3:47 pm
Wideband yagi. 138-174 mhz
http://www.sinctech.com/catalog/series.aspx?id=55
http://www.sinctech.com/catalog/resourc ... 250-DI.pdf
http://www.sinctech.com/catalog/series.aspx?id=55
http://www.sinctech.com/catalog/resourc ... 250-DI.pdf
-
Tom in D.C.
- Posts: 3859
- Joined: Tue Sep 04, 2001 4:00 pm
- What radios do you own?: Progreso soup can with CRT
That yagi...
I guess I was close enough for government work, as they say.
I've never gotten involved with or done any figuring on what is
apparently a log periodic antenna.
I've never gotten involved with or done any figuring on what is
apparently a log periodic antenna.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.