Whiskey363

What do you plan to use the radio for? If it is just to talk to family or hunting buddies I suggest something simpler like the Rocky Talkie 5 watt radio. The 935 plus was my first "real" GMRS radio and was a little overwhelming for the first 2 weeks. I can't just hand it to someone to use without instructing them as it is not intuative to non radio users. If you want to a handheld for repeaters and talking to other GMRS users in your area, the 935 is great.

Ended up measuring the Tram antenna today. Following the video Steve posted, I trimmed 5/8 inch off the first section, and about 1/4 to 3/8 of the next two sections. I have not got a chance to test it yet, but for what is worth that is how far off it was. On a side note, DX engineering is sending a new Comet CA-712EFC as I have 1.5 SWR on 462MHz and 2.5 SWR on 467MHz, and the antenna cannot be trimmed. Reading the reviews on this antenna it is hit or miss how it is cut, but the good ones are supposed to be great. We shall see.

GMRS has 22 Simplex channels (Radio to Radio) 1-22. It has 8 repeater channels RP15-Rp22. The first repeater channel available is 462.5500. This chart is helpful to be able to see it.

I will be checking the old antenna, as I will be using on a portable repeater. I will update what the length measurements were when I do that.

It is a new antenna, and of course I should of, but no I did not. It is in the 20's and windy, just wanted to get it done!

Installed 75 feet of LMR400, N Male One End, DXE PL259 with a 10 foot tall Comet 9dB antenna mounted on a 10 foot pole. As Steve mentioned would likely happen, SWR went up on the 467MHz frequencies to 2.3-2.5. I did a radio check with the repeater 15 miles away, and I got an immediate response. They could hear me with some static. Pretty impressed with 15 miles in the city with buildings and hilly terrain. I wanted to check the SWR at the antenna, but I could not figure out a way to safely do it. Either way I can hear a significant higher amount of traffic, and it is much clearer. don't know if the SWR is a concern, but at least it is clear. Thank you to everyone for your help!

Steve, that is the plan, I am just waiting for the coax so I don't have to take down the antenna twice.

That's the plan, just waiting for the new coax!

Great concise video, thank you for sharing. Could have saved the $40 and cut it to 465 from the start.

Great idea, thank you!

Being new to this I paid the seller I purchased from to trim it to "GMRS frequencies" so I would not have to deal with this, but the articles I read stated what you did. That a higher SWR on lower frequencies meant the antenna was to short and a higher SWR on higher frequencies meant the antenna was to long. When I get the new coax I suppose I will have to study how to trim the antenna, and by how much.

Thank you for the link. Are you satisfied with the performance of the antenna?

Headed to work, but thank you for your insight. Will certainly continue to research before I pull the trigger on the final coax and antenna.

I'm using the Tram 1486, but was thinking of switching to the Comet CA-712EFC 460-470MHz 9 dBi Gain Base/Repeater Antenna when they come back in stock.

Steve, With that being said what would you estimate the actual SWR reading is? From my understanding anything over 2 can damage the radio. Or is the incorrect SWR reading at the base of the radio taken into account with the 2 or lower number?

That is something I was completely unaware of. Thank you for informing me of that. At 1.8 I really can't afford for it to be any higher. Would you recommend I do not upgrade the coax? I was under the assumption this would lower the SWR as well. Thank you for your excellent, easy to understand explanation.

I did not see that calculator, thank you.

41% with 75 feet of LMR-400. That's with bumping the Load SWR from 1.5 to 1.8. That is what I currently have, so I'm keeping it constant. I'm also considering switching from UHF to Type N Connectors.

Going to take me a few weeks, but I will most certainly report the results!

I guess it depends on your definition of significant loss, but the calculator has it at a 63% power loss, which I take as significant. I absolutely agree that height is might, and I have the antenna a total of 15 feet above my roof line, which is as high as feel acceptable for the neighborhood. I could be way of base, but the fact that I can clearly RX transmissions from repeaters 15 miles away, tells my antenna is high enough. From my small knowledge base and experimentation, it is the power loss in my coax that is preventing me from TX to the repeater. Could be totally wrong, but It won't be to much of a hassle to swap it out.

LMR 240 that I currently have has me at 4.36dB loss or 22 percent more power loss than LMR 400. Seems pretty significant to me.

Thank you, very helpful!

Steve, Thank you for your reply. The problem with the coax loss calculators for the uninitiated is they are not listed as you would purchase it. There is no option for Ultraflex 7 or 10. There is RG, LMR, etc, but I can't figure out which to select.

I have a 50 foot section of Messi & Paoloni Ultraflex 7 Premium coax, and a 25 foot section that goes from the lighting arrestor to the antenna. Would it make any significant difference to replace the 50 foot section with a 50 foot section of Browning BR-400 Low Loss RF coax? I am overall pleased with my setup, can RX from 15 miles away with hilly terrain and woods. I would just like to boost my TX ability. I can send clearly 5 miles apart line of sight with my family, so my equipment appears to be in good working order, would just like to boost TX distance.

Picked up a pair on a Cyber Monday special. I was not really interested in them till I watched NotaRubicon's video on them. Tested them from inside a house to about a quarter mile away in thick woods. I was running a chainsaw and heavy equipment so I didn't have the opportunity to test everything I wanted to, like the shorter antenna. The long antenna gave excellent reception and was only slightly in the way. Since the radio is so much smaller than say a KG 935, it was really convenient to have on me at all times. The gator clip is outstanding, it's not going to randomly fall off. I thought the TX Beep would be annoying, but it was very beneficial to my daughter who was using it from the house. If you don't have much experience with a handheld you can short stroke the PTT key, but with the beep it lets you know when you've keyed and let go. I found programing to be simple and enjoyable with the manual. I think it is strange that all channels are pre set to narrow band, but easily switched. My only complaint after a day of use in the woods is when I set a DCS code, you lose that channel without a code. For instance if you save channel 18 with a privacy code, you cannot also have channel 18 with no codes to communicate with others without a code. I could be missing something, but that is my experience with it so far. If the stubby antenna works nearly as good as the larger antenna, it would be very convenient to have on you at all times without getting in the way at all. Battery life still says 100 after having on for 5 hours and using occasionally. Very satisfied with the initial run, time will tell.