External antenna for Sennheiser G2

[nhaudio]

Hi guys,

 

making my SMA's too. I've used a 'bike break' stranded wire as suggested here. The wire is too wide to fit in the small SMA pin. Are there any counter indications to strip a few wire from the strand to fit the cable into the SMA pin?

(Meaning leaving the cable as is and stripping a few wires at the pin level so around half centimeters of length.)

 

cheers 

 

[alidav]

1 hour ago, nhaudio said:

Hi guys,

 

making my SMA's too. I've used a 'bike break' stranded wire as suggested here. The wire is too wide to fit in the small SMA pin. Are there any counter indications to strip a few wire from the strand to fit the cable into the SMA pin?

(Meaning leaving the cable as is and stripping a few wires at the pin level so around half centimes of length.)

 

cheers 
I pulled out some wire to get the right tickness. works perfectly. 

 

[nhaudio]

On 7/26/2019 at 2:28 PM, alidav said:

 

thanks.

 

Here is the result. I really like the finish with plastidip.

 

[alidav]

 

these are 2 ek2000, the nr1 doesnt have the diversity antenna connected while the n2 has it, does anyone have any explanation of it? i want to take out the second sma i shoulg go from the hole on the pcb and grounding  the sma connector on the case?
the previous images are all about the g3. 

 

 

[Mikka]

Hi all,

 

 

i also made the SMA-Mod on two Sennheiser EW G3 receivers. If the first receiver reach it usable distance, the first receiver crackles but do not lose completly the connection. The secound lose it connection instantly.

 

The first receiver has the ground like that one on alidav's secound picture, the secound one has not the ground. Is it possible that the lack of the ground on the secound one is the reason? And if so, where i have to solder the ground?

 

Sorry for my bad english!

 

[LarryF]

On 7/26/2019 at 6:28 AM, alidav said:

On 7/26/2019 at 5:26 AM, nhaudio said:

Hi guys,

 

making my SMA's too. I've used a 'bike break' stranded wire as suggested here. The wire is too wide to fit in the small SMA pin. Are there any counter indications to strip a few wire from the strand to fit the cable into the SMA pin?

(Meaning leaving the cable as is and stripping a few wires at the pin level so around half centimeters of length.)

 

cheers 

 

 

Removing some strands is the correct solution. It won't hurt a thing over the short distances you are working with, i.e., much, much less than a wavelength.

LEF

4 hours ago, Mikka said:

Hi all,

 

 

i also made the SMA-Mod on two Sennheiser EW G3 receivers. If the first receiver reach it usable distance, the first receiver crackles but do not lose completly the connection. The secound lose it connection instantly.

 

The first receiver has the ground like that one on alidav's secound picture, the secound one has not the ground. Is it possible that the lack of the ground on the secound one is the reason? And if so, where i have to solder the ground?

 

Sorry for my bad english!

 

The SMA will be properly grounded when it is mechanically screwed down to the case. The case is the ground plane for the whip antenna and the case is solidly grounded to the PC board. You only need the one connection from the center pin of the SMA to the antenna input on the board. It sounds like the antenna input is somehow shorted to the ground of the system. You might see if one of the units measures differently with an Ohm meter (multimeter). However, it is possible that the normal antenna input is grounded at DC though with an inductor to ground. Look for small differences.

Best Regards,

Larry Fisher

 

[Mikka]

Thank you Larry! I didn't open the transmitter yet, but soon i will lock for the short to the ground. Maybe the case damaged the cable when I closed it. 

[hobbiesodd]

On 4/13/2016 at 10:05 PM, mark kirchner said:

This is an Ebay link for the super-elastic wire that Dave Williams wrote about. It is slightly thinner than the stock that Remote Audio uses. If you want want me to put a small sample in the mail to you just PM me.

http://www.ebay.com.au/itm/120476274177?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Hiya Mark—

 

This link is dead and was hoping to get my paws on some of that beautiful wire. I know its been four years since this post, but hopefully you have a few specs you could share that would help be narrow down my currently fruitless search? Anything would help: make, model, size, manufacturer, etc..

I need a dozen antennas for my post-mod IFBs and am trying to avoid the price tag of the Lectro/RemoteAudio options.  

 

Thanks!

Evan 

 

EDIT:

I just found another thread here for DIY sma antennas where more info on these types of wires is covered. 

I am curious, though: You wrote in 2018 that you've switched over threaded cables instead of the super-elastic solid wires. Has that been a marked improvement? And if so, which type/size have you found best works with the SMA connectors? 

[Paul F]

I'm looking into this as well. I was going to use solid spring wire, but I remembered that I have stranded stainless steel wire in a very small gauge and I tried that. I like it a lot more than solid spring wire as it is very flexible - like rubber.  It springs right back even if you bend it quite a bit. The solid spring wire tends to develop a bend much easier than the stranded wire when it is bent.

 

If your going to make antennas for the 500 Mhz and up range, the stranded stainless wire is the way to go. To make it stand up 13" for 216 Mhz that I'm doing for an IFB, I tried putting two layers of marine heat shrink tubing on it (has a glue coating on the inside). It works well. I'm more likely to use a dipole up on a pole for the 216 Mhz, but I wanted to have a whip solution as well. I don't have anything to show yet as I'm still testing and getting parts.

 

The stainless wire I have is .030" 7 strand. You should be able to get it at better hardware stores or maybe a marine store (trolling cable?).  I'm able to get at least 6 of the 7 strands in the pin.

[Paul F]

I just bought a couple of beat up Sennheiser G3 IEMs. In case you were wondering what Sennheiser used for wire; you can see the antenna wire. It looks like it is stranded stainless steel wire. It is .018" and I'm guessing it is 7 strand. Next to it is the wire I am using. As I mentioned, it is 7 strand, .030" wire. I was able to fit all 7 strands into an SMA pin. The .030" wire is very elastic and I think it may be a better choice than the .018". We'll see.  The G3 IEM is in the bottom middle of the picture. Ignore the unit on the left side of the picture. That's another discussion in the DIY forum.

[Peter Josh]

On 3/16/2019 at 8:31 AM, Texasbelch said:

I've modded my transmitter and receiver. While checking the antenna on the transmitter with my multimeter, I noticed that the antenna contact on the board is grounded with the case (meaning when set to continuity, touching one probe to the antenna connection point on the circuit board and the other probe to the case, it registers a connection). For the life of me, I can't see any stray blobs of solder. Is the transmitter antenna supposed to be grounded?

 

Hi Texasbelch,

I noticed the same thing (tested on the original Sennheiser antenna). The pin of the transmitting antenna is connected to ground. The same cannot be said of the receiving antenna. 

Did you then discover the reason?

Giovanni

[LarryF]

Hi Peter,

The antenna is most probably tied to an inductor that goes to ground. That bleeds off stray static and protects the output stage. The inductor will be 10 or 20 turns of fine wire and it will measure less than an Ohm when tested with a multimeter (DC Ohms). At the operating frequency, it will be part of the tuned output filter or will look like a high reactance, i.e., not there.

In sum, not to worry, as long as the range is "normal".

Best Regards,

Larry Fisher

[Peter Josh]

Thanks a lot Larry, I was really hoping for your reply (I always follow your very useful explanations).

 

the mod works perfectly!!!

 

 

[EMP]

On 7/26/2020 at 11:44 PM, LarryF said:

Hi Peter,

The antenna is most probably tied to an inductor that goes to ground. That bleeds off stray static and protects the output stage. The inductor will be 10 or 20 turns of fine wire and it will measure less than an Ohm when tested with a multimeter (DC Ohms). At the operating frequency, it will be part of the tuned output filter or will look like a high reactance, i.e., not there.

In sum, not to worry, as long as the range is "normal".

Best Regards,

Larry Fisher

Hi Larry,

Thanks for the explanation.

 

I have a similar question about the second antenna contact in G3/G4 bodypack receivers (the one that’s connected to the TRS sleeve).

 

To add a second SMA input, I removed the ring connecting the antenna contact to the AF Out (as sisal described above). However, the multimeter shows that the antenna contact is still shorted to the ground.

 

Is it caused by the inductor as well?

[LarryF]

17 hours ago, EMP said:

Hi Larry,

Thanks for the explanation.

 

I have a similar question about the second antenna contact in G3/G4 bodypack receivers (the one that’s connected to the TRS sleeve).

 

To add a second SMA input, I removed the ring connecting the antenna contact to the AF Out (as sisal described above). However, the multimeter shows that the antenna contact is still shorted to the ground.

 

Is it caused by the inductor as well?

I think so.

LEF