Should I swap out this contraption and get a mini immortal t antenna instead? This is how GEPRC sent me the crossfire version of the Dolphin.

I was expecting to see the immortal t antenna placed at bottom of arm but it came like this instead and moves around a lot. It feels like a prop might hit it eventually.

Oh, and off bat I'm having major issues with range. Low rssi, LQ and telemetry warnings (even losing telemetry 50 feet out). My other quad can go very far out with no problem using same nano rx. Any suggestions are greatly appreciated.

TLDR; Geprc sent me the Dolphin with a dinky looking crossfire "antenna", getting low LQ and RSSI, need help better mounting positions of antenna.

Also, I the VTX power is not showing up correctly on OSD. I can set the power up to 600mw on betaflight and it saves there, but does not show up in the OSD, it just stays at 25mw.

That actually looks alot like my mini mortal t which is the new V2. They made it flimsier to reduce weight, you can see both here. https://fpvcycle.com/products/tbs-fpvcyc...re-antenna
What power are you running your CRSF module on? Even on low setting it seems the range isn't what it should but you could try having it on at least 200mw or more just to see what happens. You could also try just moving the antenna down to an arm and hopefully that'll be enough with slightly higher power.

Not sure about the VTX power though but I would guess there's something wrong with the VTX tables. Those bastards usually are the problem x)

My Dolphin came with the T on the bottom of the frame. I've had no problems. My other quads also have the T in the same place.
I had the same junky VTX antenna and it was chopped off the first day. (first flight actually)

My suggestions:
- Move the T under the frame where it'll be protected.  
- Your VTX is probably locked to 25mw. I would remove the canopy as you'll need it off for the following steps.  While holding the VTX button down, briefly plug in/out the battery. Now that the VTX is unlocked, switch to a locked channel like Raceband 1 and choose a higher power level. You'll need to change the goggles to match.
- Go into Betaflight and select the OSD tab. Turn on the channel to see the channel and power.
- While the canopy is off, snuggle the RX to the top-rear of the canopy. It's only there as a temporary placement so you can bind....you need to move it.  Run a small zip tie through the two little holes and around the RX to secure it in place. This moves the RX away from the rest of the electronics and improves the video signal significantly.
- Next, get a lollipop antenna such as the Foxeer. Wrap the cable in layers of shrink wrap until it fits tightly in the canopy mount. (really tight). Otherwise, it's likely to get yanked off if you hit something.
- Another location for the antenna is the top-most hole. Again, do the wrapping of the cable until it's tight and solid.
- I've also wrapped a small zip tie around the VTX antenna and UFC connector and the flight controller to really tie it down. It's hard to get in there but it works. I know this removes some of the isolation of the flight controller from the frame but I didn't experience any problems.

(01-Mar-2021, 02:11 PM)patlo911 Wrote: That actually looks alot like my mini mortal t which is the new V2. They made it flimsier to reduce weight, you can see both here. https://fpvcycle.com/products/tbs-fpvcyc...re-antenna
What power are you running your CRSF module on? Even on low setting it seems the range isn't what it should but you could try having it on at least 200mw or more just to see what happens. You could also try just moving the antenna down to an arm and hopefully that'll be enough with slightly higher power.

Not sure about the VTX power though but I would guess there's something wrong with the VTX tables. Those bastards usually are the problem x)

Thanks for the reply and info! Yes, I eventually learned this is the mini immortal t, which is great for whoops and small micros but not so much for larger quads that go farther out. I am running the maximum power of 1w on the CRSF module. I moved the antenna to the arm, and range did not improve at all. OSD still showing Link Quality at 199 and very low RSSI into the teens. I have also experienced telemetry lost warnings but the quad has not failsafed or dropped out, it still remains under control? So much for BNF haha...I've been troubleshooting this since 3 days now.

(01-Mar-2021, 02:40 PM)Ljholland Wrote: My Dolphin came with the T on the bottom of the frame. I've had no problems. My other quads also have the T in the same place.
I had the same junky VTX antenna and it was chopped off the first day. (first flight actually)

My suggestions:
- Move the T under the frame where it'll be protected.  
- Your VTX is probably locked to 25mw. I would remove the canopy as you'll need it off for the following steps.  While holding the VTX button down, briefly plug in/out the battery. Now that the VTX is unlocked, switch to a locked channel like Raceband 1 and choose a higher power level. You'll need to change the goggles to match.
- Go into Betaflight and select the OSD tab. Turn on the channel to see the channel and power.
- While the canopy is off, snuggle the RX to the top-rear of the canopy. It's only there as a temporary placement so you can bind....you need to move it.  Run a small zip tie through the two little holes and around the RX to secure it in place. This moves the RX away from the rest of the electronics and improves the video signal significantly.
- Next, get a lollipop antenna such as the Foxeer. Wrap the cable in layers of shrink wrap until it fits tightly in the canopy mount. (really tight). Otherwise, it's likely to get yanked off if you hit something.
- Another location for the antenna is the top-most hole. Again, do the wrapping of the cable until it's tight and solid.
- I've also wrapped a small zip tie around the VTX antenna and UFC connector and the flight controller to really tie it down. It's hard to get in there but it works. I know this removes some of the isolation of the flight controller from the frame but I didn't experience any problems.

Yes, this is how I expected my Dolphin to come as well, but instead they opted to ship it off with a mini immortal T. I contacted GEPRC and they were not very helpful at all and even kind of rude. They said something must be wrong with my radio or CRSF module....like no, it works perfectly on my other crossfire quad. 

I moved the antenna down to the arm, range issues still remain the same. Still having RSSI in the low teens, telemetry loss (though the quad remains responsive) and Link Qualitylty stuck at 199 instead of the usual 300 I get on my other rig. 

Awesome information about the VTX! I had no idea it's probably locked. The strange thing that is confusing me is that the product description says the VTX in this quad can do up to 200mw, however, in betaflight in the VTX tab, it gives me options to go from 25mw to 600mw?? Did they change the VTX out recently for a better one? Ok, I will follow your steps now and report back when I can. Thank you!!

Weird. Maybe that's a crap antenna? I dunno. I have mini-Ts on two quads and they get pretty good range although I don't have hard numbers to support that...but I know I can go as far as I dare.

Here's a stupid question. Is telemetry even on? When I first got the Dolphin, mine was turned off in Betaflight. (configuration tab). I've heard that sometimes people turn it off because of noise but I didn't have any once I moved the RX into the canopy.

My VTX tab in BF says: 25/100/200/400/600 in the VTX table but the power is set to 200 in the actual power section. I don't think it matters if you try to go over that.

You might want to consider using the VAS XFire Pro antenna.  Here is one mounted on the rear of a 3" quad I built:



It has four holes for mounting it either with cable ties or with screws.  Two of the holes happened to line up with the rear standoffs on my frame:



I haven't done any formal range testing, but it has been working fine for me.  I've been flying the quad in the forest here lately, and I still get great signal even at quite a distance through many large trees.

(01-Mar-2021, 02:40 PM)Ljholland Wrote:

I'm no antenna expert, but I'd be wary of mounting the T across two arms like that.  The two legs of a dipole antenna are driven with signals of opposite polarity.  Having them both so close to the conductive frame would dissipate some of the signal, I think.  It's best to mount a dipole at its center, keeping the two legs away from the frame.

there are better performance and less weight antennas provided from tbs:
https://team-blacksheep.com/products/prod:mrx_antenna
https://team-blacksheep.com/products/pro...ce_ant_915
https://team-blacksheep.com/products/pro...z_mini_ufl
https://team-blacksheep.com/products/pro...8mhz_xfpro

(02-Mar-2021, 12:11 AM)SJChannel Wrote: I'm no antenna expert, but I'd be wary of mounting the T across two arms like that.  The two legs of a dipole antenna are driven with signals of opposite polarity.  Having them both so close to the conductive frame would dissipate some of the signal, I think.  It's best to mount a dipole at its center, keeping the two legs away from the frame.

This is how GEPRC sends these out, I think. They've changed the mounting style recently I believe and have swapped it to the mini immortal t (the one in my pics). I have seen others that had it mounted on one arm only and isolated from the carbon fiber as much as possible using electric tape. What would be the optimal position?

(02-Mar-2021, 01:02 AM)hugnosed_bat Wrote: there are better performance and less weight antennas provided from tbs:
https://team-blacksheep.com/products/prod:mrx_antenna
https://team-blacksheep.com/products/pro...ce_ant_915
https://team-blacksheep.com/products/pro...z_mini_ufl
https://team-blacksheep.com/products/pro...8mhz_xfpro

I have the first one on my Armattan tadpole and it works great, but I would need to make the antenna with zip ties and heat shrink and find a good orientation for that as well. The length of the wires are much longer than on this mini immortal t.

(01-Mar-2021, 09:19 PM)Elcid_888 Wrote: Thanks for the reply and info! Yes, I eventually learned this is the mini immortal t, which is great for whoops and small micros but not so much for larger quads that go farther out. I am running the maximum power of 1w on the CRSF module. I moved the antenna to the arm, and range did not improve at all. OSD still showing Link Quality at 199 and very low RSSI into the teens. I have also experienced telemetry lost warnings but the quad has not failsafed or dropped out, it still remains under control? So much for BNF haha...I've been troubleshooting this since 3 days now.

Oh I forgot to say: RSSI is worth nothing (more or less) with CRSF so you can turn that off and only look at LQ. 199 isn't too bad because if I remeber correctly that's still full signal but at 50hz where it goes 299 for full signal at 150hz. Someone please confirm that because I haven't dabbled much with LQ yet
Is your module locked to 50hz or do you have it set to dynamic?

I'm not sure what it means when the radio says telemetry lost though so someone more experienced will have to step in there.

I'm not having problems with the longer T antenna mounted along with the frame. (as shown in my picture). I have a few mini-immortal-T antennas waiting for when that antenna gets trashed. (as you know it eventually will!).

The frame on the Dolphin doesn't offer any mounting options for that flat antenna
https://team-blacksheep.com/products/pro...8mhz_xfpro

I'm not sure how I'd mount the wire one.
https://team-blacksheep.com/products/prod:mrx_antenna

along the frame is bad as carbon can detune the signal, but i did it too and it worked without any issue for my short range use.

i -believe- you can turn the antenna around the receiver and it would still out perform the mini imortal-t :-)

as suggested: between the arms, main plate, is a good practice friendly option, two ziptie mounted on the battery-strap-mount, some shrink...
mount it vertical would be better but not friendly for practice, until you like to go 5k+