The plastic pins that allow the stock antenna on my TX12 to rotate broke. The antenna still works, but I figure I should replace it before the wire breaks, and would like to upgrade to a better antenna if it makes sense. Any suggestions? I have an order close to ready at Pyrodrone, so that would be a good source, or of course Amazon for free shipping and returns.

The original antenna has an RPSMA female connector.

Thanks.

Buy one on AliExpress or alibaba it’s like $3. Or I can sell you one, I have like 2 from diy ELRS modules

(28-Jun-2023, 03:43 AM)luispequeno Wrote: Buy one on AliExpress or alibaba it’s like $3. Or I can sell you one, I have like 2 from diy ELRS modules

Cool. I'm not finding it on AliExpress when I search for tx12 antenna. Can you provide a link?

What would you charge and how would we arrange the transaction?

Any thoughts on upgrading to a better antenna, and whether or not it would make any difference?

Thanks!

This is what I use on my external 2.4ghz ELRS module, and I’ve got no complaints.
https://pyrodrone.com/collections/radio-...-t-antenna

It doesn’t have a hinge to bend/break.
It has an rp-sma male connector, which is what you need according to the Radiomaster stock antenna replacement for the tx12:
https://www.radiomasterrc.com/products/t...enna-rpsma

If it’s the actual bit that the antenna screws onto that you need, you’d probably be better off buying it from Radiomaster at the link above, since that way it will come with the plastic part.

(28-Jun-2023, 08:59 PM)Lemonyleprosy Wrote: This is what I use on my external 2.4ghz ELRS module, and I’ve got no complaints.
https://pyrodrone.com/collections/radio-...-t-antenna

It doesn’t have a hinge to bend/break.
It has an rp-sma male connector, which is what you need according to the Radiomaster stock antenna replacement for the tx12:
https://www.radiomasterrc.com/products/t...enna-rpsma

If it’s the actual bit that the antenna screws onto that you need, you’d probably be better off buying it from Radiomaster at the link above, since that way it will come with the plastic part.

Yeah, I saw the Radiomaster one. It's weird that it has a male connector, as mine has female connector--at least that's what I'd call it:



I see that they also sell a female connector, which I guess I swap for the male in the radio?

The reason that I keep asking about an upgrade is that ELRS is supposed to have great range, but I tried flying my Cinebot a bit away from the park yesterday, and I only got a few blocks away when I started getting weak signal warnings. Also, the signal strength seems to drop quickly once it starts dropping.

I don't know if this is just because of too much EM interference in the city environment, or something with the receiver or transmitter.

RP means reverse polarity. It unnecessarily complicates things, but, with rp-sma the male has a socket and the female has a pin.

Regarding your range, I’d suggest doing a ELRS bench test to make sure everything is as it should be.
https://www.expresslrs.org/quick-start/p...bench-test

A good article from Oscar about lq, rssi, and rssi dbm:
https://oscarliang.com/lq-rssi/

(29-Jun-2023, 09:24 PM)Lemonyleprosy Wrote: RP means reverse polarity. It unnecessarily complicates things, but, with rp-sma the male has a socket and the female has a pin.

Regarding your range, I’d suggest doing a ELRS bench test to make sure everything is as it should be.
https://www.expresslrs.org/quick-start/p...bench-test

A good article from Oscar about lq, rssi, and rssi dbm:
https://oscarliang.com/lq-rssi/

Thanks for explaining RP--I was wondering if it was something weird like that.

I'll try the bench test and read Oscar's article. Thanks.

I neglected to mention that I have link quality and RSSI dBm value displayed in my goggles, and I record everything.

The values when I first launch are 98-100 and about -60 dBm. 

Flying around the park, typical values are about  and -75 dBm and 100, with ranges from about -60 dBm to -80 dBm 90-100, with link quality closer close to 100 more than not, and RSSI more in the upper range.

I also display my Tx uplilnk power; I have my TX set to use 250 mW (max), Dynamic--mostly to conserve battery when playing sims, although I'm not doing that much these days. It starts out at 10 mW, and stays there much of the time, but will jump to 25, 50, 100 mW sporadically throughout flying around the park.

While writing this, I decided to just do the bench test. I see 100 and -45 to 42 dBm. The RSSI value is a bit below the range of -40 to -30 dBM, but it's close, and with a link quality of 100, isn't that OK? My TX reads 10 mW in the OSD during the test, which is the value the bench test requires.

Now I'm looking for the readings when I started getting weak signal warnings; back shortly ...

OK, llnk quality indicator in OSD starts flashing at about -80, but it drops so fast to lower numbers that it's really hard to tell where it starts. RSSI is about -80 dBm at that point. The lowest LQ reading I note is 12, at which time RSSI is -85. All I do is turn a bit toward home, and LQ jumps back to 100, with RSSI at -86, but then quickly increasing to -77 or so.

As I recall, the radio starts giving me audible signal strength warnings when the LQ readout starts flashing, so I don't push it after that.

Radio is 250 mW throughout at the limits. It reduces to 100 mW at 99 and -73 dBm.

As a reminder, the pivot pin on the antenna is broken, but the wire appears to be OK.

What’s your packet rate?

500 Hz. I had it set to 250, and then read some stuff about 500 being a good setting for FPV.

The ELRS bench test article said that packet rate didn't matter much for that test.

Just a question for you. Are you matching your antenna polarization? I've seen a lot of people put a horizontal T or sleeved dipole on their receiver, but then point their transmitter antenna up vertical. Gotta match them if you want the strongest possible signal. If they're currently unmatched, your signal is actually looking pretty good for now.

(01-Jul-2023, 07:12 AM)Suros Wrote: Just a question for you. Are you matching your antenna polarization? I've seen a lot of people put a horizontal T or sleeved dipole on their receiver, but then point their transmitter antenna up vertical. Gotta match them if you want the strongest possible signal. If they're currently unmatched, your signal is actually looking pretty good for now.

The TX antenna is the stock monopole antenna that comes with the radio.

I believe I had the antennas matched for the bench test, but I ran it again with this setup:



The antennas are aligned in the z axis and tilted at about the same angle in the y axis; not sure the latter matters.

Here are the parameters and the results:

ELRS bench test
Distance 1 meter
Distance 39.4 inches
TX power 10 mW
Packet rate 500 Hz
RSSI max -41 dBm
RSSI min -50 dBm
LQ 100

The RSSI varied over time, and kind of got locked into a higher or lower reading for a period of time.

I changed the packet rate to 250 Hz, and it made no noticeable difference.

I don't know what the best TX antenna position is in the field, since obviously the RX antenna is all over the place. I generally put it in about the same position as for the bench test.

I am going to order the Radiomaster T Antenna to see if that makes a difference.

Is that the Cinebot30 that you've previously mentioned in other threads? If so, the RX null is pointing towards your TX and you're cross polarized. To see proper performance, point the TX antenna tip at the wall and aim the flat part of the RX T at your TX. With monopoles and dipoles, you want them parallel and avoiding the tips as often as possible.

Edit: You know, I can't actually tell which way your quad is facing. Still, you're definitely cross polarized like that.

(02-Jul-2023, 09:12 AM)Suros Wrote: Is that the Cinebot30 that you've previously mentioned in other threads? If so, the RX null is pointing towards your TX and you're cross polarized. To see proper performance, point the TX antenna tip at the wall and aim the flat part of the RX T at your TX. With monopoles and dipoles, you want them parallel and avoiding the tips as often as possible.

Edit: You know, I can't actually tell which way your quad is facing. Still, you're definitely cross polarized like that.

Yes, that's the cinebot30.

Thanks, I'll try again with the antennas aligned as you say.

What position do you recommend the tx antenna in the field?