Jump to content
  • 0

HITTING A REPEATER WITH GM-30


WalkaWalka
 Share

Question

6 answers to this question

Recommended Posts

  • 0
12 hours ago, WalkaWalka said:

Hey there my Radio Friendly Units, I just got 2 RADIODDITY GM-30s. I am on RPT 2 FOR 462.575MHZ and dialed in the proper CTCSS CODE HZ. Is there something I am not doing correctly to get on the repeater? 

These radios aren't the Star Trek communicators seen on TV. They suffer from an entire range of issues regarding antennas, power output and terrain. First of all, standing where you are could you see where the repeater is? If there is anything blocking your  view such as buildings, hills or mountains, fuggitaboutit. The second thing is if you could literally see where the repeater is, how far away are you? More than 10 miles with a clear line of sight is iffy at best. That's where output power comes into play - not only your handneld, but the repeater's output as well.Third is the antenna,the little stubby antennas on your radio is radiatting less power than your radio is rated at - period - statement of fact. How much the power is reduced depends on how the antenna is made and you aren't going to fix that.

The primary key to increasing the range from any radio is how high above the average height of the terrain surrounding your radio. The HAAT (Height Above Average Terrain) of the antenna is the most important piece regarding range. As GMRS type radio waves radiate in a virtual straight line the range is how far away is the horizon from the antenna. By law, the amount of output power for GMRS is fixed so the theoretical range is also fixed depending on the antenna height. In other radio services the FCC uses the HAAT of an antenna to limit the output power. So, the range your radio has is limited by these three factors. 

Now, speaking of codes, a code is used to further limit the number of stations on the same frequency being heard. If the code does not match, the radio does not process the signal to the speaker. When programming in codes, do not limit your receiver to only "hearing" if a code is sent, most repeaters only use an input code which your transmit sends. So, leave the receive frequency set to no code unless specifically required. This is the most likely reason you can't receive a repeater signal when a transmit code is required. It's so easy to assume a receive code is also needed when in fact the code is blocking the signal.

Link to comment
Share on other sites

  • 0
13 hours ago, WalkaWalka said:

Hey there my Radio Friendly Units, I just got 2 RADIODDITY GM-30s. I am on RPT 2 FOR 462.575MHZ and dialed in the proper CTCSS CODE HZ. Is there something I am not doing correctly to get on the repeater? 

The first thing I'd check is the presence of the repeater. Are you certain the repeater is within range and is operating? You may have already done so, but if not, contact the repeater owner to find out if the repeater is functioning, obtain the current codes/tones needed for access, and to get permission to use the repeater (unless it's designated as open for use by others).

If you're just depending on a repeater listing from this site, you may find that listed repeaters no longer exist, or they now use a different frequency and/or CTCSS/DCS code.

I use my GM-30 to access a private (unlisted) repeater quite often and generally, I am able to do so reliably within several miles when relatively within line of sight. I can get through the trees in the forest and over/around small hills without too much trouble. It's mostly the bigger hills and mountains that limit my range, and the fact that the repeater is in a valley, and not on a mountain top.

Link to comment
Share on other sites

  • 0

Great information posted here about the limitation of using a handheld radio and being able to "hit" a repeater. I currently live on top of a hill, the highest point in the area, and have GMRS and P25 repeaters within only a few miles of my house. However, due to the metal foil insulation used in the house, I must be close to certain windows, or on an outside desk to hit both GMSR and P25 repeaters. The P25 repeater is for work, and there is also simulcast coverage in the area as well, both impacted just as the GMRS repeaterand my ability to reach them via handheld, by the metal foil insulation. Mobiles do better, with outdoor antennas and more power to get through the windows, but the handhelds are already lower power, less capable antenna (even with a counterpoise "rat tail"), and effected by the human body holding it as well. Thank you all for sharing information.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Guidelines.