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Author Topic: gap titan  (Read 2403 times)
WA1TTL
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Posts: 4




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« on: October 18, 2013, 12:21:15 PM »

Hello,

I just recently put up a gap titan dx. I cannot get the antenna to resonate on 30 meters at all and it is resonating on 80 meters at the very start of the band 3.5 Mhz. At 3.520 the swr is 2 to 1 and 3 to 1 at 3.530 and up from there. I have adjusted the counterpoise as Gap tech support has suggested. I can certainly see this making a difference on 40 meters but no change on 80 meters.  Has anyone had similar problems with the titan? I previously had a Gap challenger and never had any problems resonating on 80 meters....Thanks
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W8ATA
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« Reply #1 on: October 18, 2013, 06:06:00 PM »

Just for starters, do you have to correct capacitor mounted in the tip of the top tube? It comes with two, one for 80M and one for 75M.

73,
Russ
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KB6HRT
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« Reply #2 on: October 18, 2013, 07:40:29 PM »

Had one of these antennas about 7 years ago when I was looking for a vertical that would hopeful do 75m after I was able to get working on all bands with some work, found on 75 meters it was down a lot compared an of my wire dipoles, its a hard antenna to tune and even when you get it, there are lots of verticals that I had better results with on 75m check my review under my call sign for my results, since then was able to get better result with other verticals, last vertical I used was the Zero 5 10-40 ground plane which does 75m as well and is a lot stronger on receive on 75m an took 20 min to put up.  KB6HRT
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WA1TTL
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« Reply #3 on: October 19, 2013, 08:34:56 AM »

Yes, the antenna came with the cap assembly at 3.9 mhz. I got another one from Gap fpr the CW poetion of 80eters
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K3VAT
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« Reply #4 on: October 19, 2013, 02:32:58 PM »

<SNIP>
... it is resonating on 80 meters at the very start of the band 3.5 Mhz. At 3.520 the swr is 2 to 1 and 3 to 1 at 3.530 and up from there. I have adjusted the counterpoise as Gap tech support has suggested. I can certainly see this making a difference on 40 meters but no change on 80 meters.  Has anyone had similar problems with the titan? I previously had a Gap challenger and never had any problems resonating on 80 meters....Thanks

Your readings are about what is expected for the Gap Titan on 80M.  The 2:1 SWR bandwidth on these compromise antennas is very narrow: ~ 50khz  (you may get more with a bit of fine-tuning, some good fortunate, and having an antenna system that is out in the open [away from other objects, especially metal ones]).  If you have a 1:1 at 3.500 the antenna may be a bit long.  If you are an Advanced Class and want to work CW on 80M a good place for the 1:1 SWR is 3.540 to 3.550 mhz.  There you should be able to cover the lower portions of CW (above 3.525) and also the digital portion of 80M if you are interested in PSK or JT65 with a decent SWR that should be easily matched with most any tuner.

GL, 73, Rich, K3VAT


 
« Last Edit: October 19, 2013, 03:22:48 PM by K3VAT » Logged
WA1TTL
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« Reply #5 on: October 21, 2013, 07:12:18 AM »

Thanks Rich...I am betting this is resonating certainly well below 3.5 mhz. I believe GAP says the the usueable bandwidth is 100 Khz on 80 meters below 2:1 swr. I would certainly think I need to shorten the antenna to get the resonant frequency up. My question is with the Gap how do I accomplish this. As I was saying earlier, I can adjust the counterpoise and this has quite an effect of 40 meters but5 no effect on 80 meters.  My Titan is about 5 ft. off the ground.


Matt
WA1TTL
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K3VAT
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« Reply #6 on: October 21, 2013, 07:28:54 AM »

Thanks Rich...I am betting this is resonating certainly well below 3.5 mhz. I believe GAP says the the usueable bandwidth is 100 Khz on 80 meters below 2:1 swr. I would certainly think I need to shorten the antenna to get the resonant frequency up. My question is with the Gap how do I accomplish this. As I was saying earlier, I can adjust the counterpoise and this has quite an effect of 40 meters but5 no effect on 80 meters.  My Titan is about 5 ft. off the ground.
Matt WA1TTL

Matt,
Page 11 says, "The length of the Counterpoise Hoop controls the center frequency on 40m."
Page 14 Section 7.1 has several suggestions for problems if you are unable to resonate on 80M and their phone number if you need help.

You may want to try a service call with GAP - they are the ones that really know the antennas and may be able to help out.

Also, you can search the archives from this Forum as this topic has come up before: http://www.eham.net/ehamforum/smf/index.php?action=search - you may need to vary the search wording to get what you're looking for.

GL, 73, Rich, K3VAT
« Last Edit: October 21, 2013, 07:31:09 AM by K3VAT » Logged
WA1TTL
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« Reply #7 on: November 18, 2013, 09:31:52 AM »

 I ended up taking the capacitor assembly out of my old Gap Challenger and putting it into the Titan. Problem solved, My Titan is now resonating at 3.550 Mhz. I must have received a defective assembly from Gap which I have sent back to them

                                              Matt....WA1TTL
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K2DC
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« Reply #8 on: November 19, 2013, 02:01:12 AM »

Even when you get the match straightened out, I think you'll find that the Titan's performance on 75M is typical of all GAP antennas on their lowest advertized band.  For several years I had a GAP Eagle (40M-10M) mounted about 20' above the ground.  It did reasonably well on 20M and up, but on 40M my dipole at 35' beat the snot out of it - Even for DX.

73,

Don, K2DC

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K3VAT
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« Reply #9 on: November 19, 2013, 07:07:46 PM »

I ended up taking the capacitor assembly out of my old Gap Challenger and putting it into the Titan. Problem solved, My Titan is now resonating at 3.550 Mhz. I must have received a defective assembly from Gap which I have sent back to them

                                              Matt....WA1TTL

Matt,
Good troubleshooting and repair.  Hope to hear you on 80M sometime.
73, Rich, K3VAT
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