Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Measuring SWR on Diamond MR77 with 2M HT  (Read 5606 times)
N4NYY
Member

Posts: 4778




Ignore
« on: August 10, 2012, 09:37:32 AM »

I am about to purchase a Diamond MR77 so I can use my FT-60 in the car. Must be a magmount because I frequent parking garages for work. Anyway, I have a Diamond SX-200 SWR meter that will measure 2M, but not 440.

Since this is my first voyage into mobile 2M and measuring SWR on 2M, can I simply measure the SWR in FM mode? I have only done it in HF up til now on AM.
Logged
KA4POL
Member

Posts: 2000




Ignore
« Reply #1 on: August 10, 2012, 10:34:40 AM »

No problem, yes, you can.
Logged
N4NYY
Member

Posts: 4778




Ignore
« Reply #2 on: August 10, 2012, 02:03:04 PM »

No problem, yes, you can.

This is like my first trip into VHF land. I went on a fox hunt last Sunday. I am starting to like it.
Logged
KA4POL
Member

Posts: 2000




Ignore
« Reply #3 on: August 10, 2012, 09:54:17 PM »

This may just be the beginning. All of a sudden antennas are getting handy. And at 10 GHz and above you may need a course in plumbing.
Logged
K6LCS
Member

Posts: 1548


WWW

Ignore
« Reply #4 on: August 12, 2012, 09:48:43 AM »

Why do you want to measure SWR with an HT and a mag mount antenna?

If the antenna is new - and there is no squished or kinked cable - then just use it.

Clint K6LCS
Logged

Clint Bradford, K6LCS
http://www.work-sat.com
N4NYY
Member

Posts: 4778




Ignore
« Reply #5 on: August 12, 2012, 10:27:48 AM »

Why do you want to measure SWR with an HT and a mag mount antenna?

If the antenna is new - and there is no squished or kinked cable - then just use it.

Clint K6LCS

From Diamond's installation instructions: http://www.diamondantenna.net/pdfdocs/MR77.pdf

3. Install antenna on vehicle. With a quality VSWR meter, check VSWR. The MR77 and MR77SMA are pre-tuned, and should require no adjustment.


IOW, just check to be sure. 

Logged
KA4POL
Member

Posts: 2000




Ignore
« Reply #6 on: August 12, 2012, 10:41:43 AM »

Much better than finding out the hard way  Cheesy
Logged
K6LCS
Member

Posts: 1548


WWW

Ignore
« Reply #7 on: August 12, 2012, 12:11:28 PM »

OK. Check SWR on everything you do.

The original poster has a 4-5W HT, and a good quality mag mount that is already tuned for best performance on 2M and 440. Personally - and if the antenna is new - I wouldn't drag out a SWR meter to the car to test it. My resulting signal reports will let me know how well my 4-5W are hitting local stations/repeaters.

Change the equation, though, with different radio and/or antenna, then my answer might be different ... (grin)

Clint K6LCS
Logged

Clint Bradford, K6LCS
http://www.work-sat.com
N4NYY
Member

Posts: 4778




Ignore
« Reply #8 on: August 12, 2012, 01:47:30 PM »

OK. Check SWR on everything you do.

The original poster has a 4-5W HT, and a good quality mag mount that is already tuned for best performance on 2M and 440. Personally - and if the antenna is new - I wouldn't drag out a SWR meter to the car to test it. My resulting signal reports will let me know how well my 4-5W are hitting local stations/repeaters.

Change the equation, though, with different radio and/or antenna, then my answer might be different ... (grin)

Clint K6LCS


I do not understand what you are saying. Are you saying that if it were the case that the SWR were high because of a defect or something, that it would not do damage do the HT because it is 5W?

I am using a 5W HT as of now. Will likely go to a higher wattage mobile later. Still, for the time it takes to check SWR, it is kind of lazy to NOT check it, just because it is new. And please do not tell me that you have never gotten anything new, that did not work out of the box, ever in you life.
Logged
K1WJ
Member

Posts: 455




Ignore
« Reply #9 on: August 23, 2012, 11:39:41 AM »

Modes to test swr: FM,AM,CW. I have MR77 - works good for me. 73 K1WJ David
Logged
AB0RE
Member

Posts: 293




Ignore
« Reply #10 on: August 23, 2012, 04:38:08 PM »

I think what Clint is saying is that you'd be surprised (and not in a good way) to see what the SWR is on most rubber duck antennas.  It's nothing for them to see a 3:1 SWR regularly (it varies wildly depending on where you are when you transmit) and the HT does fine.  In other words, it'd be good advice to check the SWR, but if you're TX/RX signals are okay you can bet the SWR is no worse than what your HT has seen via the rubber duck antenna.
Logged
K1CJS
Member

Posts: 6034




Ignore
« Reply #11 on: August 24, 2012, 04:27:51 AM »

I do not understand what you are saying. Are you saying that if it were the case that the SWR were high because of a defect or something, that it would not do damage do the HT because it is 5W? ...

If you actually looked at the SWR of the rubber duckie antenna that came with your HT, you would more than likely get a shock--it would probably be sky high.  Most rubber duckie antennas are little better than dummy loads.

The importance of low SWR is just about always overblown.  It is nice to get that SWR low, but you don't have to get it way down to 1.1 to 1--it probably wouldn't be possible anyway.  Anything below a 2 to 1 SWR reading is good.  It's when you have readings of 3 to 1 or higher that your rig may have problems.
Logged
KA4POL
Member

Posts: 2000




Ignore
« Reply #12 on: August 24, 2012, 08:12:01 AM »

Most rubber duckie antennas are little better than dummy loads.

Unbelievable! To my experience dummy loads are much better than rubber duckies. I mean real dummy loads.
Logged
K1CJS
Member

Posts: 6034




Ignore
« Reply #13 on: August 28, 2012, 06:22:41 AM »

....I mean real dummy loads.

You're right!  And it isn't because it's hard (impossible) to put an RF connector on those 'real' dummy loads either!   Grin
Logged
KD4EBL
Member

Posts: 75




Ignore
« Reply #14 on: August 28, 2012, 09:20:52 AM »

I think it is a good idea to check SWR yearly or when you think there is a problem and write down the results. That way you can compare it to the last time you checked it. When I first got my mag mount, I checked it after moving the mag mount several places on the roof and trunk to see where I would get the best results. Intresting how the result would change, even by moving the antenna a couple of inches. I also check all my rubber duck antennas to see how they fair and get rid of them if they start to go south.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!