New HAM with fading issue

[WSEL330]

Elmer/Elmo/Radio dorks/Etc..(not meant to be derogatory, affectionate),

     As the title says, I am new (KR4FHF). I have a TYT TH-9800. Getting at 1.01-1.65 SWR between freqs on 70cm and 2m. Coax is rg58 (I know....And length in this case made no difference with my problem). Antenna is about 60' up but I am on a wooded lot. I have it in as clear of a spot as I can hanging from a tree. I adjusted the height according to SWR. Repeaters report decent signal report. I have been on nets with no one saying anything about my trans. While listening, the speaker will start strong with great signal. Then the audio degrades but signal the same. I find if I 'key' quickly, the speaker comes back strong again but then fades again. My HAM study suggests that my radio does not have the features to 'track the fluxuating freq' OR I have a problem with capacitance and/or inductance somewhere. Surprisingly, the antenna tuned for 70cm and 2m works with an SWR of 1.2 on my GRMS tuned at a 462.575ish. I have swapped the coax cables back and forth (RG58 and RG213) as well with no change in fading. I this a product of my location and propagation problems due to my climate? Need some learnin', enlighten me oh wise HAM family.

[WRUU653]

I’m curious what you are using for a power source.

[WSEL330]

2 minutes ago, WRUU653 said:

I’m curious what you are using for a power source.

Jesverty SPS-3011 set at 13.8V

[WRUU653]

Just now, WSEL330 said:

Jesverty SPS-3011 set at 13.8V

Well that shoots down that theory… 

[WSEL330]

1 minute ago, WRUU653 said:

Well that shoots down that theory… 

But thank you, Sir.

[SteveShannon]

26 minutes ago, WSEL330 said:

Elmer/Elmo/Radio dorks/Etc..(not meant to be derogatory, affectionate),

     As the title says, I am new (KR4FHF). I have a TYT TH-9800. Getting at 1.01-1.65 SWR between freqs on 70cm and 2m. Coax is rg58 (I know....And length in this case made no difference with my problem). Antenna is about 60' up but I am on a wooded lot. I have it in as clear of a spot as I can hanging from a tree. I adjusted the height according to SWR. Repeaters report decent signal report. I have been on nets with no one saying anything about my trans. While listening, the speaker will start strong with great signal. Then the audio degrades but signal the same. I find if I 'key' quickly, the speaker comes back strong again but then fades again. My HAM study suggests that my radio does not have the features to 'track the fluxuating freq' OR I have a problem with capacitance and/or inductance somewhere. Surprisingly, the antenna tuned for 70cm and 2m works with an SWR of 1.2 on my GRMS tuned at a 462.575ish. I have swapped the coax cables back and forth (RG58 and RG213) as well with no change in fading. I this a product of my location and propagation problems due to my climate? Need some learnin', enlighten me oh wise HAM family.

That sounds like a problem with the radio. Can you contact customer service and maybe get a replacement?

[WRUU653]

The “quick keying brings it back momentarily” has me suspicious of a loose connection in the radio and the additional power demand is temporarily making the connection better. I’m with @SteveShannon on contacting customer service. 

[WSEL330]

2 minutes ago, SteveShannon said:

That sounds like a problem with the radio. Can you contact customer service and maybe get a replacement?

Bummer, I'll see what I can do...Any low budget options for this type of Radio (70cm-2m). Course I am going for my general and realize I will have several radios eventually as the rabbit hole swallows me up!

[SteveShannon]

2 minutes ago, WSEL330 said:

Bummer, I'll see what I can do...Any low budget options for this type of Radio (70cm-2m). Course I am going for my general and realize I will have several radios eventually as the rabbit hole swallows me up!

The Radioddity db20g is a 20 watt GMRS radio that is easily unlocked to operate on 2m and 70 cm. Several of us have one or more. 
Best wishes for your general!!

[WRUU653]

Real budget I like the Anytone AT-779 or one of it’s equivalents. 

[WRUU653]

1 minute ago, SteveShannon said:

The Radioddity db20g is a 20 watt GMRS radio that is easily unlocked to operate on 2m and 70 cm. Several of us have one or more. 
Best wishes for your general!!

You beat me to it

[SteveShannon]

6 minutes ago, SteveShannon said:

The Radioddity db20g is a 20 watt GMRS radio that is easily unlocked to operate on 2m and 70 cm. Several of us have one or more. 
Best wishes for your general!!

 

5 minutes ago, WRUU653 said:

Real budget I like the Anytone AT-779 or one of it’s equivalents. 

@WSEL330 - just so you know the AT-779 and the Radioddity are basically the same radio, just different name plates. There’s another brand also that sells their version of the same radio but I’m old and I don’t remember the name.

[WRYS709]

9 minutes ago, WRUU653 said:

Real budget I like the Anytone AT-779 or one of it’s equivalents. 

I find that my AT-779UV and my DB20-G into to my rooftop Comet CX-333 tribander, outperform my Yaesu FT-857d on 2 meters and 70 cm FM. 

[WSEL330]

3 minutes ago, SteveShannon said:

 

@WSEL330 - just so you know the AT-779 and the Radioddity are basically the same radio, just different name plates. There’s another brand also that sells their version of the same radio but I’m old and I don’t remember the name.

I share your old thing, that's why I ask via type so I can look back at it!

[WRUU653]

13 minutes ago, SteveShannon said:

 

@WSEL330 - just so you know the AT-779 and the Radioddity are basically the same radio, just different name plates. There’s another brand also that sells their version of the same radio but I’m old and I don’t remember the name.

Retevis RA25. I had to look it up, I couldn’t remember either

[WRUU653]

10 minutes ago, WSEL330 said:

I share your old thing, that's why I ask via type so I can look back at it!

If memory serves me (and sometimes it doesn’t) I believe all three can be unlocked but you can also order either GMRS or ham versions as well. 

[WRYS709]

8 minutes ago, WRUU653 said:

Retevis RA25. I had to look it up, I couldn’t remember either

I have never had a Retevis Ra-25 in my hands, but in an attempt to help a Ham that had one, I found that the Retevis version of the CPS software created codeplugs that I could not open in the Radioddity CPS software. 

So I have concluded that the Retevis model is not a 100% clone and I avoid it. 

Chirp (and/or the RT Software) may make this issue moot!

[WRXB215]

Don't forget to check out the AnyTone 778UV while you're at it.

[WSEL330]

18 minutes ago, WRXB215 said:

Don't forget to check out the AnyTone 778UV while you're at it.

Thank you all. My first stop is call/contact them and see what can be done....

[AdmiralCochrane]

This is why I bought the extended warranty on my 9800.  Not this exact problem, but numerous similar problems.  Mine has been great.

[WRYZ926]

The TYT TH-9800 seems to have more issues that other TYT radios. I have a couple of TYT TH-7800 dual band radios that have not had any issues. I agree that you should contact the seller about your issues. There is an issue with your radio.

Now while RG58 is working for you, RG8 and LMR400 (or equivalent) will work better. If your coax run is 60 feet then your ERP -effective radiating power is going to be around 48 watts.

Here is the line loss per 100 feet of coax and ERP for 60 feet of coax for the 2m band

RG58 - 70% 48 watts

RG8 - 44% 70 watts

LMR400 - 32% 79 watts

Same numbers but for the 70cm band

RG58 - 90% 25 watts

RG8 - 66% 52 watts

LMR400 - 48% 67 watts

Same numbers for GMRS repeater frequencies

RG58 - 91% 27 watts

RG8 - 67% 50 watts

LMR400 - 49% 66 watts

I used the https://kv5r.com/ham-radio/coax-loss-calculator/ to get those numbers. I used an SWR of 1.7 and antenna gain of 3 dBd. A higher gain antenna will have a higher ERP.

You really are doing yourself a disfavor by using RG58. Stay away from the cheap junk coax from Amazon and eBay. Buy the best quality coax that you can afford.

[Bogieboy01]

On 9/5/2025 at 6:19 PM, WRUU653 said:

Real budget I like the Anytone AT-779 or one of it’s equivalents. 

Was gonna reccomend the 778uv, which i own 2 of, or finding a good deal on a used anytone 5888uv, which i also own... great radios for the price.... 

[Destro]

On 9/5/2025 at 4:27 PM, SteveShannon said:

 

@WSEL330 - just so you know the AT-779 and the Radioddity are basically the same radio, just different name plates. There’s another brand also that sells their version of the same radio but I’m old and I don’t remember the name.

Yes the Retevis RA25, and now Abbree also has one on Amazon. And it's $10 cheaper than the others.

[Destro]

[WRUU653]

17 minutes ago, Destro said:

Yes the Retevis RA25, and now Abbree also has one on Amazon. And it's $10 cheaper than the others.

Just an FYI, It's possible that one of the other radios chirp file will work with it but chirp isn't listing for the Abbree specifically at this time.