Tram 1410 and TxWarn

[Enforcer52]

I have a Bearcat BCD325P2 that I have been running with a $10 mobile antenna stuck to the edge of my metal roof home (about 12' in height). I live on Lake Livingston in San Jacinto County and was able to pick up San Jacinto, Polk, Trinity and Walker counties with no problems, all are within 30 mile radius.

I purchased a Tram 1410 antenna and placed in the same location as the mobile at around 22' in height. I immediately noticed that the Walker County (Huntsville) TxWarn system no longer worked and am scratching my head as to why. Connected the mobile back up and Huntsville TxWarn went back to working. Even connected my Diamond RH377A and could receive the Huntsville TxWarn stations with no problem standing in the front yard.

Any ideas as to why the TxWarn system will not work with the Tram 1410?

 

[KF5ARD]

The Tram 1410 does not cover 700/800 mhz.

Tram Broad Band Base Antenna (144/220/440/900/1290 MHz)​

 

[Enforcer52]

Well that explains it, guess it gets returned.

Does the Diamond D-130J cover the 800 mhz band?

​

 

[hiegtx]

The Tram 1410 does not cover 700/800 mhz.

Tram Broad Band Base Antenna (144/220/440/900/1290 MHz)​

That's incorrect. That coverage, which shows on this page, is misleading. It's a discone antenna. It won't simply "skip" the 700 to 800NHz frequencies, but then include 900MHz. Discones are not "gain" type antennas, but can work for a wide frequency range.

If you look at the description on this model from The Antenna Farm (among others), you'll see "Frequency: 25-1300 MHz".

 

[hiegtx]

I have a Bearcat BCD325P2 that I have been running with a $10 mobile antenna stuck to the edge of my metal roof home (about 12' in height). I live on Lake Livingston in San Jacinto County and was able to pick up San Jacinto, Polk, Trinity and Walker counties with no problems, all are within 30 mile radius.

I purchased a Tram 1410 antenna and placed in the same location as the mobile at around 22' in height. I immediately noticed that the Walker County (Huntsville) TxWarn system no longer worked and am scratching my head as to why. Connected the mobile back up and Huntsville TxWarn went back to working. Even connected my Diamond RH377A and could receive the Huntsville TxWarn stations with no problem standing in the front yard.

Any ideas as to why the TxWarn system will not work with the Tram 1410?

For the Tram antenna, are you using a different coax cable from what your original antenna uses? If so, what type cable are you using? How long is the cable run, from the antenna to your scanner inside the house? Is your roof mounted antenna similar to one of these? Did you purchase coax for it with the connectors already on it, or used a length of cable & added the connectors (on either, or both ends)?

I think the handheld antenna you list, RH377A, is typo'd. That's not a valid model. Are you referring to the Diamond RH-771 or RH77CA? (Those two are basically the same antenna, with a small difference in length. (The RH-771 is the Japanese model; RH-77CA is the US market version.)

Since you can receive that site using a handheld antenna, standing in your yard, as well as on your original antenna, it sounds as if there is a problem either with one of the connectors in the Tram setup (on the antenna itself, of one of the connectors on the coax). Another possibility is either the coax cable has too much signal loss, or there is a break somewhere in the cable.

A less likely scenario is that by moving to an antenna mounted higher, you are getting interference from another transmitter, such as a cell tower, or broadcast TV. The Walker County site involved is not a simulcast one, so it's not simulcast distortion.

 

[Ubbe]

The size of that discone makes it a 90MHz-500MHz antenna. It will still have a low SWR up above 900MHz but its performance are degraded above 700Mhz as its radiation pattern do not cover the horizon at the highest frequencies, maybe 10dB loss or more at the angle of the horizon.

If you do not need full performance at VHF, its at least line of sight to aircrafts that can be heard with any antenna type, then cut all top elements and all bottom elements to half size and the discone will have good performance up to 1000Mhz.

You could try and cut just the top elements to go half way with the modification and that might be equal to your other antennas but still have some improved VHF air performance and also at 137-160MHz if you have weak signals in that range that you would like to monitor. You can always solder the element ends back on, a 1/2 inch shorter doesn't matter, or use a screw terminal of some sort perhaps tube clamps to restore the discone to original performance.

/Ubbe

 

[Enforcer52]

Thanks for the replies. Ended up taking my pl-259 to bnc connector and screwing directly to the antenna, and put the BCD325P2 handheld scanner directly on the bnc connector. Had only the Huntsville TxWarn system activated. Hoisted it back in the air, and listened for 30 minutes.
Nary a peep out of the scanner.

Hooked the mobile antenna back up and receiving Huntsville with no problems, although only getting 1 to 2 bars signal, was hoping the Tram 1410 would pick up a better signal, but didn't expect nothing at all..

Thanks again for everyone's help.

 

[phoboss1]

I never had luck with the Tram Discone. I got a Diamond Antenna discone and got better results.

 

[hiegtx]

Thanks for the replies. Ended up taking my pl-259 to bnc connector and screwing directly to the antenna, and put the BCD325P2 handheld scanner directly on the bnc connector. Had only the Huntsville TxWarn system activated. Hoisted it back in the air, and listened for 30 minutes.
Nary a peep out of the scanner.

Hooked the mobile antenna back up and receiving Huntsville with no problems, although only getting 1 to 2 bars signal, was hoping the Tram 1410 would pick up a better signal, but didn't expect nothing at all..

Thanks again for everyone's help.

I'm still leaning toward some sort of coax or connector problem, rather than the Tram being the "wrong" antenna, Granted, it's a discone, which does not have any gain. And those long vertical radial rods appear to trend it's reception toward lower frequencies.

I go back to what I asked before, and was not answered.

For the Tram antenna, are you using a different coax cable from what your original antenna uses? If so, what type cable are you using? How long is the cable run, from the antenna to your scanner inside the house? Is your roof mounted antenna similar to one of these? Did you purchase coax for it with the connectors already on it, or used a length of cable & added the connectors (on either, or both ends)?

What type coax are you using? And, how long is the cable.

While not likely, it's also at least possible that the antenna itself is defective. If you have a VOM, check for continuity between the center contact of the SO239 (the antenna's connector) and one of the antenna's radials.

 

[Enforcer52]

25' of RG8X with factory BNC connectors for mobile, 15' of RG8X with factory SO239 connectors with SO239 to BNC to connect to the 25' cable when connected to the Tram.

Tried with just the 15' cable with no 800mhz reception only vhf/uhf , tried just the SO239 to BNC with SO239 connected to Tram and scanner (scanner) hanging on bottom of antenna directly antenna tied to pole to raise up, with no 800mhz reception only vhf/uhf.

Didn't meter the antenna out with cables attached, since cables worked no problems with on vhf/uhf, metered cables, no shorts.

Just doesn't seem to be any gain on 800mhz at all. Tram boxed up waiting on UPS tomorrow to pickup.

Put the mobile antenna on top of pole raised it up and now getting 2-3 bars on 800mhz, so guess in my area the mobile works better than the Tram for 800mhz, and vhf/uhf are booming in.

 

[Brales60]

You guys know way more than me, but had a Tram Discone, nope, went to a Sirrio Discone, nope. Went to a Omni X, and golden. Most of my stuff is 700-800, but air isn't an issue either. Very pleased with this unit up 20'.

 

[Enforcer52]

You guys know way more than me, but had a Tram Discone, nope, went to a Sirrio Discone, nope. Went to a Omni X, and golden. Most of my stuff is 700-800, but air isn't an issue either. Very pleased with this unit up 20'.

Since I live in a very mixed band area with 150mhz regular, 150mhz P25, MOT2, MOT2 Simulcast all in a 30-35 mile area, the Omni X might be worth checking out. Thanks for the tip.

 

[Brales60]

So, just turned FL Forestry back on which in the 150's, no issues at all. Lots of action due to a T storm. Clear as heck.

 

[mmckenna]

As stated, discone antennas have zero gain and their radiation patterns can get funky at the higher end of their range.

You didn't tell us what type of mobile antenna you have. I'm betting it's something with gain at 800MHz and a more appropriate radiation pattern.

If it is working with the mobile antenna, why are you looking for a new antenna?

 

[Enforcer52]

I have a Bingfu 20-1300 mhz mobile antenna, a Diamond RH377CA scanner mount, the scanner BCD325P2, but I use it in the car, roaming around town with the Diamond, and most of the time at home, so that is why I wanted a good home antenna. I ordered an Omni X today and will try that out.

 

[mmckenna]

I have a Bingfu 20-1300 mhz mobile antenna,

OK, if it's the magnet mount vertical, then that would likely have some gain on 800MHz, and that would explain why it is working better than the discone. So, not really a surprise in my book.

a Diamond RH377CA scanner mount, the scanner BCD325P2, but I use it in the car, roaming around town with the Diamond, and most of the time at home, so that is why I wanted a good home antenna. I ordered an Omni X today and will try that out.

Looking at the Omni-X, there are no published gain figures for 800MHz. I'd be prepared for it to not be a large improvement for the cost.

If the Bingfu is working, and you just want another mobile or base antenna, there are less expensive ways to do that for less money.

 

[madrabbitt]

+ the multiband NMO of your choice, plus the correct length coax.

TECHNICALLY the groundplane on that is only decent to UHF, but most multiband antennas provide gain on 800.

 

[Ubbe]

The Omni-X have two VHF dipoles tuned to two different frequencies angled in an X that doesn't give any gain when they are tilted like that. For UHF 225-900MHz it is vertical tube used as a dipole. All three dipoles are connected in parallel and interact with each other. Look in the wiki how a balun must be used with a dipole and I don't know if Omni-X have one.

Dipole antenna - Wikipedia

en.wikipedia.org

Below are the pattern for a discone at half it's lowest frequency, then 1x and 3x and 6x. I.E. 50-100-300-600MHz
If a discone are cut to half size it lowest frequency will be doubled. Cut to 2/3 size and it will be 1,5x higher.
Its lowest frequency are given by the length of the bottom elements as in a 1/4 wave length. Tram1410 are 33" 85cm = 90MHz and are at 6x 550MHz and any higher in frequency it gets worse. All discones behave in the same way due to its design.

/Ubbe

 

[Enforcer52]

Got my Omni X this afternoon and got it put up 20-21'. Made a world of difference! I am on Lake Livingston outside of Onalaska, on the San Jacinto County side of the lake.

I noticed a 1-3 bar increase in raw signal strength across the board. Audio quality is much better. So far am picking up stations in 60 mile radius of my location. Even picking up Waller County SO which is 70 miles away, and north Harris Co SO.

Am slowly rotating position of the Omni X to see where it gives me best coverage.

Thanks for everyone's help.

 

[iamhere300]

Got my Omni X this afternoon and got it put up 20-21'. Made a world of difference! I am on Lake Livingston outside of Onalaska, on the San Jacinto County side of the lake.

I noticed a 1-3 bar increase in raw signal strength across the board. Audio quality is much better. So far am picking up stations in 60 mile radius of my location. Even picking up Waller County SO which is 70 miles away, and north Harris Co SO.

Am slowly rotating position of the Omni X to see where it gives me best coverage.

Thanks for everyone's help.

Well, Waller SO is on TXWARN, so.... But Fire Dispatch is still on VHF.