Amateur (Ham) Radio BS and Callsign Thread!

@cheuer an SWR meter is the best tool for troubleshooting this kind of issue. I don't know about super cheap options but a nano VNA is a great tool and does more than just SWR measurements.

It seems unlikely that transmitting into an open feedline would cause permanent damage to your Kenwood but it is of course a bad idea. Most modern radios have circuitry to reduce power if your radio has a bad impedance on the antenna output. It is still possible it damaged the radio but not first on my list. I also highly doubt a mismatch on transmit that damaged your transmit power amplifier section would damage your receiver as well. A bad antenna system does affect transmit and receive though.

Most likely culprit is the feeling or antenna itself. The trouble with DC measurements on RF lines is that something that passes DC may not pass RF. Mobile installations are subject to a lot of vibration that like to break wires. If you used solid wire RG-58, I wouldn't be surprised if the coax is compromised internally.

I still say you need a good bond between your antenna mount and the metal under it but not everyone agrees with that. If your mount isn't piercing through the powder coating but it worked well before, that probably isn't your problem.

Since you don't have good test equipment, try your dad's antenna then try his coax if you can.

Of if you can find another ham in your area, maybe you can meet up and have them check your feedline and antenna. Most hams that I know are willing to help out that way.

 

NR770HNMOB doesn't require a ground. I have one mounted on my plastic motorcycle luggage rack.

SWR meters are frequency specific, specially the cheap ones. CB models wont work correctly on V/UHF. You can now get chinese network analyzers on Amazon for less than $100, but they're more complicated than just watching a moving needle.

What is your RFI situation? UHF is trashed in my 3rd gen. I wouldnt be able to do simplex with engine running. Strong repeaters only.

 

Thanks I'll look at this.

The feedline is a Larsen NMOKHFUD which I bought because of my previous issues with a self-soldered nmo mount coming loose. The center pin is inserted of course. On the radio end is this connector, yes I soldered in the center wire.

Could I just run a standard automotive wire from the mount to a ground somewhere under the cab? I've seen the metal braided bonding straps but it looks like they aren't really long enough to reach any ground on the truck.

This is something I hadn't considered, I guess I should do some tests with the engine off. We are operating on VHF simplex. Is it possible to reduce the RFI with something?

 

How did you secure the shield? Did you solder the shield to the barrel? I have always had trouble soldering those shields so I moved to crimp type shield connectors.

That's not likely to change much if it changes at all. People use copper braid because it presents a low impedance at all frequencies. @golfindia mentioned it doesn't need a ground and the manual suggests that as well. Swap your antenna with your dad's and see how it works. It looks like your antenna is an NMO base still. Is the center spring contacting the antenna where you screw it on?

VHF and UHF work fine in my 3rd gen. HF is troublesome but that's not an issue here. My setup is a little different than yours though; potentially a little more "robust".

 

The connector screws on which makes contact with the shield, I didn't see any way to solder it.

However, the nano vna came in today and I think you were right about a break in the cable. Got both of these readings with the same connections by moving the cable around a bit. Going to look at shortening it tomorrow, I think it's near the end based on messing with the cable there and it was making a pretty sharp bend. The radio body is mounted under the driver's seat, I wonder if one of the times I had it getting worked on a tech moved the seat all the way back.



I'll report back if that fixes it or not, thanks again for the help.

 

Possibly. I have a decent service loop on all the cables going to my TM-D710G base under the seat so it can move a lot before pulling tight. Glad you found it.

 

Yeah tried to leave more slack this time. I wasn't able to get it finished before going over to my dad's last night for dinner so don't have a report back yet but I'm pretty sure this is the issue. There wasn't a break, but a really sharp bend.

 

I'm not seeing a GMRS thread, so I guess this is the best spot to ask:
comparing radio antennas

Currently have this:
https://www.amazon.com/gp/product/B00XQAY7WI/

Seeing this marketed as a potential upgrade:

$25 Authentic Genuine Nagoya NA-F30G 30" Tactical Foldable Whip GMRS/MURS (155/465MHz) Antenna SMA-Female for BTECH and BaoFeng Radios

https://www.amazon.com/gp/product/B0BZ59WT5D/

Is it? It sure seems more robust. I've already caught the NA-717 on clothing/car doors/branches enough times to bend it right at the base, then have to straighten it out (best I can).

 

Seems very similar to the ABBREE antenna I've heard about here. Good things from what I've heard though I've never used one. There's also Signal Stuff Signal Sticks https://signalstuff.com/products/#signalsticks . Both seem like they would be more flexible than what you currently have but no antenna will stand up to endless abuse if you hit it at the base.

@golfindia Good timing, 40m was hot last night with the CWops Contest (CQ CWT). I listened just a little before bed, probably 200 signals on the waterfall.

 

Oh, this one?

$9 ABBREE SMA-Female Ham Radio Antenna VHF/UHF 18.8" 144/430MHz High Gain Foldable CS Tactical Antenna for Baofeng UV-5R BF-F8HP Pro 5RM K5PLUS GM21 AR-152 Quansheng K6 UVK5(8) Radio (1)

https://www.amazon.com/ABBREE-Foldable-Tactical-SMA-Female-Connector/dp/B07GYKN6ZD?th=1

It seems to have good reviews as well.

 

Yes, though now looking at it, that's a chunky base! Check out Josh's video: https://youtu.be/KDBC0azUa50
Looks like there are several different lengths too.

 

At a certain point you have to remember that you're slapping it on a handheld that can only do so much anyway.

 

https://www.dxengineering.com/parts/dmn-srj77ca

They work great and are flexible.

 

N5MKH / WRQH258 here. Just puled my TYT TH9800 (Quad Band that I only Dual Band) out of the Ranger I sold and looking to get it into the Tacoma. This thread is sitting at 458 pages of light reading so I'll be scouting through to find a good spot to mount the radio, face, and antenna. Looking at the area over the driver side tail light with the Rago (SP?) mount. Now I just need to get a good High Gain antenna. Will probably measure height this weekend and see what my appetite for altitude is and then keep it under that.

If the Rago works out I might get one for the other side and get a switch so I can have 2/70 on one side and 6/10 on the other. But the radio is only FM and those are dead bands around here so maybe not.

 

I run a Kenwood V-71A and put the radio under the driver’s seat with the faceplate above the rear view mirror under the headliner.

 

I did similar to @vssman but the face was on the bezel above the infotainment system. Now I have a TM-D710G setup the same way I had my TM-V71A.

 

When I took my test, I missed one question. They asked me if I wanted to take the General test on the spot. It was during a Hamfest, so it might be a little different.

 

What did you do now?