a Short question.... Tram 3500 has a short???

[niceguy71]

hey guys
I've been watching youtube video's and reading..... seems the Tram 3500 magnet mount 57" CB antenna is fantastic.... people getting some fantastic range!!!! so I bought one..... I also read a few people got them and they had a short in them???? so before I tried it I got my ohm meter out and touched it to the center pin and the outside piece that threats onto the back of the radio... see pictures.... it was a dead short???? so I mailed that back and got another one.... same thing.... so I went and did the same test on my K-40 magnet mount ..... no problems... before and after testing the meter showed 1.... so I returned that one for a refund..... today I got my third one.... guess what... yup dead short on it???? am I reading these wrong???? ... with the wires touching center pin and outside threads I get 000 a perfect contact..... not touching the wires I get a 1 meaning nothing conducting....

 

[dave3825]

Testing CB Antenna for High SWR Readings

strykerradios.com

 

[mmckenna]

It depends on the coil design. Some coil designs are DC grounded, some coil designs are not. Without knowing what kind of coil it uses, I'd not guess at what it should be showing, but it may not indicate an issue.

Also, if you are expecting to see a 50Ω load, you won't. 50Ω impedance at 27MHz is different that 50Ω DC resistance that your meter would show into a 50Ω resistive load.

 

[niceguy71]

It depends on the coil design. Some coil designs are DC grounded, some coil designs are not. Without knowing what kind of coil it uses, I'd not guess at what it should be showing, but it may not indicate an issue.

Also, if you are expecting to see a 50Ω load, you won't. 50Ω impedance at 27MHz is different that 50Ω DC resistance that your meter would show into a 50Ω resistive load.

OH NO!!! never in my wildest dreams would I think a dead short would be ok???? guess I sent a couple back for no reason... I'll go hook to my truck and press the mike key and pray I don't see smoke. ...but it has 100% conductivity from pin to screw piece.... I've never seen that.... maybe I should see if I can contact Tram, thanks Mmckenna

 

[mmckenna]

The DC grounded coil would be transparent at 27MHz. I've got VHF antennas that do the same thing, all totally normal.

Best way to confirm that is to use an SWR meter. You should do that anyway. Even if it is a problem with the antenna, a short transmission isn't going to hurt your radio.

Let me know if you do hear something from Tram.

 

[niceguy71]

The DC grounded coil would be transparent at 27MHz. I've got VHF antennas that do the same thing, all totally normal.

Best way to confirm that is to use an SWR meter. You should do that anyway. Even if it is a problem with the antenna, a short transmission isn't going to hurt your radio.

Let me know if you do hear something from Tram.

I just got off the phone from Tram.... long process to get the phone number ( almost impossible) but I charmed several women in sales and support and got a great guy.... he said some do that and are meant to be like that. he wasn't sure of the 3500 but said a lot of the Tram commercial antenna's do that... he said just try it! ... so I guess I'll go try it... ...I read several people that had shorts and the antenna's didn't work and made the radio's act funny.. so I didn't want to take a chance!... I guess I shouldn't have listened to the reviews. ...I'll let you know if it works

 

[W9WSS]

I've had several antennas on multiple frequencies that showed "dead short" when I connected a DVM to the center conductor and the ground. They all worked just fine.

As mmckenna said, it may just be a DC grounded antenna. This is normal.

 

[mmckenna]

I just got off the phone from Tram.... long process to get the phone number ( almost impossible) but I charmed several women in sales and support and got a great guy.... he said some do that and are meant to be like that. he wasn't sure of the 3500 but said a lot of the Tram commercial antenna's do that... he said just try it! ... so I guess I'll go try it... ...I read several people that had shorts and the antenna's didn't work and made the radio's act funny.. so I didn't want to take a chance!... I guess I shouldn't have listened to the reviews. ...I'll let you know if it works

I'm surprised you reached a human. I'm not surprised they didn't know the answer.

Tram/Browning is a shell company that sells Chinese antennas that are usually clones of legit antennas. Years ago they showed up at one of the LMR conventions/trade shows and I made a point of talking to the guy. He didn't seem to really understand much about antennas.

Knowing if a coil was DC grounded or not should be something the vendor would know.

Despite what most CB'ers will want you to think, the CB isn't going to produce a small mushroom cloud of fire/smoke if the SWR is high. That's not the way things work. Connect an SWR meter and do it right. You should tune the antenna for your exact installation, anyway.

 

[niceguy71]

ok I hooked up the Tram 3500 on the truck... I also put my President grant Export in just temporarily sitting on the seat... that Tram 3500 is WHIPPY! I went around town with it and it's up there gotta be 12 feet high.... lot less leaves on the trees in my town now... but it stayed put.... I even took a chance on driving it into the garage it's so whippy I thought maybe just maybe...well it did make it in!!!! ... I'll try and see how it gets out of the garage tomorrow. the K-40 was so stiff I wouldn't even try it.
OK TEST RESULTS
I dead keyed it on channel 20 and got 15 watts..... ,, I then unkeyed the mike ...I put it on SET and the needle was all the way to the left... I keyed the mike and turned the adjustment knob and I turned it all the way till it stopped and the knob could not be turned anymore, the needle only went to the middle of the meter????? see picture on channel 20 I tried a few things but always the same.... no way to get the needle all the way to the right for SWR SET....... I did not get much noise... maybe 1 DB and I also heard nothing but static with the squelch down..... I did faintly pick up a little on 19 with the squelch down all the way... I thought I would try 38 LSB and listened for 20 minutes nothing on it.... I also tried a radio check on it... funny it only put out 11 watts on sideband... it's always done 25 watts???? so I guess I'll buy another SWR meter... but I think that antenna is junk.... I am trying to replace the coax on one of the K-40's I have so I didn't try it.. I have two other K-40 antenna's but I could not get them connected to the magnet mount to see what the SWR meter would do.... hopefully tomorrow. ......the wire on the K-40 needs to go through the back of the trunk lip mount in order to put it on the magnet mount,,,, but the Connector is too big to go through so I'll be doing some research tonight and tomorrow I'll see if the old SWR meter will go to SWR SET with a different Antenna.

 

[mmckenna]

Usually you put the meter switch in the "normal" or "forward" position, key the mic and set the knob so the meter shows full deflection (highest mark on the right side of the meter)
Unkey the mic. Set the switch to "reverse" or SWR and key the mic. It should then show you the reflected power or SWR.

As for the power output on SSB, that's going to vary depending on the modulation level. You would need to talk into the mic (or, God forbid, whistle) to see what the true output is.

Your antenna may need to be tuned. If the SWR is high, it'll impact the power output.

Don't give up on it yet.

 

[niceguy71]

Usually you put the meter switch in the "normal" or "forward" position, key the mic and set the knob so the meter shows full deflection (highest mark on the right side of the meter)
Unkey the mic. Set the switch to "reverse" or SWR and key the mic. It should then show you the reflected power or SWR.

As for the power output on SSB, that's going to vary depending on the modulation level. You would need to talk into the mic (or, God forbid, whistle) to see what the true output is.

Your antenna may need to be tuned. If the SWR is high, it'll impact the power output.

Don't give up on it yet.

I was just going to say what is he talking about??? normal or forward... I don't have that on my meter.... so I just looked at the meter picture above and see a SWR SET... sun of a gun I've forgotten how to do the simplest things!!! I'll go try it again.... I flipped the middle WHITE switch to SET and thought it was that easy!... I think I turn the knob to SWR SET then key the mike and turn the adjustment knob till the needle sits on SWR SET then turn the knob to SWR to read it??? I think I'll leave the white switch in the middle to set.. I'll be back in 20 minutes

 

[mmckenna]

You sound like me. If I don't do something frequently, I forget.

So, yeah, however that meter is set up. You do need to set/calibrate it to the power output of the radio. Then set it back to read SWR and it should give you what you need.

 

[niceguy71]

You sound like me. If I don't do something frequently, I forget.

So, yeah, however that meter is set up. You do need to set/calibrate it to the power output of the radio. Then set it back to read SWR and it should give you what you need.

ok I think I did it right.... on channel 01 I have 2.4 SWR... on Channel 20 I got 2.1 SWR and on Channel 40 I got a 2.0... not looking to adjust it now... I am just looking to see if the Antenna is working or shorted... if it was shorted I think the SWR would be even worse! so I am thinking it's ok.... a while back... I listened to a couple of smart guys on here about RF bonding and still need to bond the cab to the bed and the cab and bed to the frame and also the hood to the cab... then I'll adjust the SWR
so do you think the Antenna is working??
I feel like a complete idiot forgetting how to do a simple SWR reading.. if I had a ham license I think I would have to mail it back!

 

[niceguy71]

PS.... the Tram 3500 made it out of the garage for the SWR test and it made it back in!... but it's got to bend the devil out of everything... not sure I want to keep doing that... but it sure would be simple and nice to always have my CB at my side ready to turn on at a moments notice.

 

[mmckenna]

so do you think the Antenna is working??

Sounds like it's working.
And don't be surprised by the lack of radio traffic thing, it can really be hit and miss. 38 or 6 may come alive at different times of the day. The local traffic may be harder to hear, as most are running half-arsed radio setups that don't work well and have short range.

I feel like a complete idiot forgetting how to do a simple SWR reading.. if I had a ham license I think I would have to mail it back!

No, welcome to the club. Like I said, if it's something I haven't done in a while, I find I forget. Pulling out the manual is usually a requirement on my end. Went through that a few weeks ago at work, completely forgot how to do something and had to spend some time 'remembering'.

 

[mmckenna]

PS.... the Tram 3500 made it out of the garage for the SWR test and it made it back in!... but it's got to bend the devil out of everything... not sure I want to keep doing that... but it sure would be simple and nice to always have my CB at my side ready to turn on at a moments notice.

Yeah, eventually something is going to give.

 

[niceguy71]

ok I hooked up the Tram 3500 on the truck... I also put my President grant Export in just temporarily sitting on the seat... that Tram 3500 is WHIPPY! I went around town with it and it's up there gotta be 12 feet high.... lot less leaves on the trees in my town now... but it stayed put.... I even took a chance on driving it into the garage it's so whippy I thought maybe just maybe...well it did make it in!!!! ... I'll try and see how it gets out of the garage tomorrow. the K-40 was so stiff I wouldn't even try it.
OK TEST RESULTS
I dead keyed it on channel 20 and got 15 watts..... ,, I then unkeyed the mike ...I put it on SET and the needle was all the way to the left... I keyed the mike and turned the adjustment knob and I turned it all the way till it stopped and the knob could not be turned anymore, the needle only went to the middle of the meter????? see picture on channel 20 I tried a few things but always the same.... no way to get the needle all the way to the right for SWR SET....... I did not get much noise... maybe 1 DB and I also heard nothing but static with the squelch down..... I did faintly pick up a little on 19 with the squelch down all the way... I thought I would try 38 LSB and listened for 20 minutes nothing on it.... I also tried a radio check on it... funny it only put out 11 watts on sideband... it's always done 25 watts???? so I guess I'll buy another SWR meter... but I think that antenna is junk.... I am trying to replace the coax on one of the K-40's I have so I didn't try it.. I have two other K-40 antenna's but I could not get them connected to the magnet mount to see what the SWR meter would do.... hopefully tomorrow. ......the wire on the K-40 needs to go through the back of the trunk lip mount in order to put it on the magnet mount,,,, but the Connector is too big to go through so I'll be doing some research tonight and tomorrow I'll see if the old SWR meter will go to SWR SET with a different Antenna.

WA0CBW noticed in the picture I was transmitting but the CB meter wasn't moving... and sun of a gun if he wasn't right.. more stuff to look at... going to be 91 here tomorrow... but I may have to see what's going on with wit old President Grant

 

[niceguy71]

I watched a youtube video of a guy I always enjoy watching he gets 20 miles range on his Tram 3500 with a 4 watt CB ... he always does a video showing it mile by mile ... pretty scratchy by the end but close to 20 miles....so I e-mailed him just to triple check and sure enough his antenna shows a short also.... I'm dumbfounded I always thought that would be a short. ... awful lot to know about this Radio hobby.

 

[mmckenna]

I watched a youtube video of a guy I always enjoy watching he gets 20 miles range on his Tram 3500 with a 4 watt CB ... he always does a video showing it mile by mile ... pretty scratchy by the end but close to 20 miles

There are so many variables that you may or may not have control over. Atmospheric conditions are a big part of that right now. Local topology, noise floor, your exact setup, etc.

awful lot to know about this Radio hobby.

Some of us have made it into a life long career.
Antenna design is an entire field of study on its own.


Couple of things to try:
Tune your antenna.
Make sure your CB is powered off a clean power source. Needs to have the + lead directly to the vehicle battery. Ground the - lead close to the radio.
Unplug any other noisemakers in your car. USB cigarette socket chargers are often very noisy.
Take your truck out in the middle of nowhere, away from power lines, street lights, homes. Shut the truck off, sit and listen.
Make sure your RF gain is turned all the way up (if your CB has that feature).

Sit and listen. The amount of traffic you hear will vary depending on the time of day.

 

[niceguy71]

There are so many variables that you may or may not have control over. Atmospheric conditions are a big part of that right now. Local topology, noise floor, your exact setup, etc.



Some of us have made it into a life long career.
Antenna design is an entire field of study on its own.


Couple of things to try:
Tune your antenna.
Make sure your CB is powered off a clean power source. Needs to have the + lead directly to the vehicle battery. Ground the - lead close to the radio.
Unplug any other noisemakers in your car. USB cigarette socket chargers are often very noisy.
Take your truck out in the middle of nowhere, away from power lines, street lights, homes. Shut the truck off, sit and listen.
Make sure your RF gain is turned all the way up (if your CB has that feature).

Sit and listen. The amount of traffic you hear will vary depending on the time of day.

thanks Mmckenna as always great advice. .... I know you can't judge by the mile... I was watching the guy on youtube... he has tested many Antenna's he always stops at the same spots each mile he stops and transmits and shows the DB on the base station ...his tests made the Tram 3500 look pretty good and the one he leaves on his car for the last 6 years... that's why I thought I would try it... he did a K-40 test the got about the same mileage... both the Tram 3500 and K-40 were close... both beat the Wilson 1000 and most of the others he's tried... he did one on a President new york... tiny little thing and I think he got 5 miles... that is awesome for a 19.7" antenna!... it's HOT in Massachusetts right now so I may wait for a cooler day to finish setting up the mobile....... I don't do well in this heat.