Can someone out there suggest a very good vhf only base antenna? I'm looking to put up on a mast a good VHF only antenna 150-170Mhz. I am also going to change my rg58 to LMR 400 unless someone has a better suggestion.
VHF Base station antenna
- Thread starter Rawkee1
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mmckenna
I ♥ Ø
A single bay folded dipole like the Telewave will probably outlast your home. A bit pricey, but absolutely in the "very good" category.
The type of coax you need depends on the length. Without knowing how long the run is, it's hard to say if there is something better than LMR-400 for your specific application.
prcguy
Member
If you feel like rolling your own post #5 in this thread has plans to make a 4-bay dipole array that covers most of the range your looking for. I made one and it works really well.
forums.radioreference.com
4-bay VHF dipole array project
This project was inspired by someone wanting a better antenna for VHF RR and this is about the best you can get. It will cover 2m through RR and can be custom tweaked if you have an antenna analyzer. The pdf instructions are a first draft, but it took longer to document the project than it did...
Ubbe
Member
A Diamond F23 I suggested in another thread have very low wind resistance, doesn't weight much and are easy to install. It consist of 3 elements stacked vertically at 5/8 wavelength each. That diopole project suggests using copper tubing. It will be heavy and copper starts to corrode almost immediately in wet conditions and RF travels only on the surface of the elements so you will have to protect them with a coat of paint if you plan to build one.
/Ubbe
/Ubbe
prcguy
Member
The copper dipole elements are very lightweight, its thin hollow tubing. The project plans mention painting everything and I've had a version up in the air near the ocean since 2008 and its fine. The 4-bay dipole array will have noticeably more gain than the Diamond F23 and Diamonds gain figures are a bit inflated. The problem with a stacked colinear like the Diamond is the spacing between elements is not optimum to produce the best pattern and gain. The dipole array is.
Ubbe
Member
You can never trust antenna manufactures that are selling to the private public. They say 7.8dB but in relation to what? My reception seems to correspond to some 5dB gain when compared to a 1/4 GP and a 3 element yagi, so if it was dBi it is pretty close. And their antenna pattern diagram looks to be pure theoretical. But antenna was cheap and easy to install in 10 minutes and saved me a lot of work as I was first considering building a 4-stacked dipole antenna that requires exact measurements in everything to make it work good. Maybe easier to do if you have lots of previous experiance of building antennas.
/Ubbe
/Ubbe
There are so many antennas on the market. One of the best antennas I had was that discontinued channel master that was simple and it had elements that looked like pitchforks on it.
I see a ferret antenna from Scannermaster but it’s very expensive and I’ve read no reviews on it. I would shell out the money if it worked really great. In theory, it really should perform really well. I have about a 45 foot run of coax that I’m changing to LMR400 from rg58u.
@Rawkee1 The Channel Master Monitenna / AKA Scantenna or ST2? If so, that interesting antenna works rather well over a wide range. I use one, but it is discontinued as you noted.
If you do not want to build one, and $300+ is expensive, you can have one custom made for less.
dpdproductions.com
If you do not want to build one, and $300+ is expensive, you can have one custom made for less.
Custom Vertical Outdoor Base Antenna
Note: When checking out, please enter the frequency you would like the antenna tuned to (between 137 and 460 MHz) in the 'notes' field. Specs Gain: 3 to 4 dBi SWR: 1.5:1 or Less Pattern: Omni-directional Wavelength: 1/2 Elements: 1 Tuned: To Order Band: To Order Connector: N Female...
dpdproductions.com
The antenna looked very similar but I believe the one I had was made by Channel Master and I remember buying it for about $39 brand new. One of the best antennas that I owned. It’s still on the roof of the house I sold. Does that DPD dipole have good reviews? The $129 doesn’t seem too bad if it performs well. I want a good antenna while I’m doing both the coax and antenna change out. I’m not a big fan of the discone antennas. I had an old cb antenna that worked better than the discone so I took it down.
Ubbe
Member
That F23 at the same cost will beat it hands downs. I have a 1/2 wave dipole, a 5/8GP, a 3 element yagi and the Diamond F23H all for VHF and the F23 are superior to all, and receives in all other frequency bands, more or less. So it's not dead outside of VHF.
/Ubbe
Thanks Ubbe. That is a good comparison of antennas. I have heard good things about the F23. I'm curious as to what cable you are using on these antennas?
Ubbe
Member
I use RG6 on everything as it is so easy to route and doesn't cost much. I have only systems up to the 470MHz limit in my country so loss are less than 1dB even on long coax lengths.
/Ubbe
/Ubbe
prcguy
Member
I hope the OP understands the Diamond F23 does not cover 150 to 170MHz continuous, its a narrow band antenna that must be custom tuned to a specific frequency between 144 and 174MHz. As shipped it covers most of the 2m amateur band but will not work well at the 157Mhz marine band or above unless you tune it there, but if you cut it for 157 you will loose performance in the amateur band, etc.
This antenna is going to be used primarily for 158-161mhz. I guess I should cut it to get the best performance for those frequencies. I'm still pondering on the coax though. I only have a fifty foot run. I'm not sure exactly how much I'll gain for reception using LMR400 or Rg8x vs RG59.
Was it the channel master 5094A antenna? I have one and it works good.
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prcguy
Member
If your going to the trouble of a dedicated gain type antenna then why skimp on the coax? I would use LMR400, its become the standard for moderate runs needing low loss at a reasonable price. Use RG-8X or RG-6 and someone will always point out you went the cheap route, you will always doubt your choice. Get LMR400 and your done, nobody will complain and you will have good performance with no regrets.
Ubbe
Member
You can check that with one of the coax spec tables. LMR400 have 0.5dB at VHF for a 50ft run. RG6 has 1.5dB, RG8x has 1.8dB, RG59 are 2dB and RG58 3dB. If you have a receiver that can show dBm you can see how much those dB will degrade reception. One S unit on a S-meter are 6dB. If everything has a perfect 50 ohm load to the coax you will loose another 0,4dB using 75 ohm RG6 coax. Perfect match means 1.0:1 in SWR but that never happens. My SDS100 has the lowest VHF SWR at 1.5 @137MHz and at 150MHz it's 2.0 and 175MHz are 2.5 and 2.0 means it's could be either a 25 ohm or 100 ohm impedance.
If you use an amplifier at the antenna you will of course have no losses and much better constant impedance to the coax if you also use an isolating splitter at the receiver, and a constant load to antenna and receiver regardless of SWR in the coax. Amplifiers often have lower noise figures than a scanner or SDR dongles, that makes you gain at least 2-3dB just from the lower noise. Then add the gain from not having coax and connector losses. I can't be without amplifiers as it improves reception so much during weak signal monitoring.
/Ubbe
It was the Channelmaster 5094 antenna I had. I was told by a family member it's in my other house in the attic. I will go and look because that was a great antenna. Does anyone know about this dipole on ebay New! Super Scanner Two XC Base Antenna, 4 Separate Antennas Inside!? It caught my eye and wondering if it has acceptable performance. I was also wondering where I can get an amplifier that goes up near the antenna. That interests me and I am going to go with the best coax. I'm learning a lot for all your input. I getting back in the game but things have drastically changed from when people bought crystals then PPL programming like with the Pro 2006. So much more options now. I really want to know if that dipole I mentioned above would be worth it.
I owned an Austin Ferret antenna for several years but I wouldn't recommend it to anyone. It performed similarly to smaller, much less expensive antennas, although the specs would have you think otherwise. I left it in the attic of my former house when we moved.
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