88-108Mhz 13 Element Log Periodic – (Band II) LPA Commercial Antenna



88-108Mhz 13 Element Log Periodic - (Band II) LPA Commercial Antenna

A 13 Element LPA (Log Periodic Array) for the 88 to 108Mhz (Band II)

£630.00 — £660.00

Product Code – 88108LOG13FM
A 13 element LPA (Log Periodic Array) for the 88 to 108Mhz (Band II) Commercial FM band. This is a truly awesome antenna for the discerning enthusiast or broadcast professional. At 6m in length it’s big and produces performance figures to be proud of. The antenna exhibits a excellent gain figure of just under 12dbi across 80% of the whole band and a front to back between 15.8 and 43db. Originally developed as a 12 element version, we found that by adding a single parasitic element purely for the higher frequencies at the front of the array, it gave positive results generally across the whole range. Hence from the model, the feed location is on the 2nd element with the front element being a pure parasitic which is not phased within the LPA Array.

During testing an S9 signal from a local station on 102MHz could barely be detected when the antenna was rear on, suggesting rejection figures of over 40db which backs up the EZNEC plots of very high front to back ratios in the low and mid-band areas. The antenna is manufactured from Vortex commercial grade 6082-T6 aluminium, including our premium grade element tubes together with full stainless fittings and Stauff hardware. A bespoke phasing line is used to obtain an optimum impedance value. When fed with 50 or 75 ohms balanced line or coax, the array exhibits a nice shallow SWR curve across the whole band. Between 88 and 97Mhz the forward gain is just under 12dbi with over 30db front to back ratio in some areas with minimal side lobes.

Large antennas such as this also come complete with an additional horizontal support. This support is used to reduce boom sag and anchors the boom both front and rear which reduces the sag and sideways movement of the boom. For our guying line we use ‘Mastrant’ 4mm synthetic guy line which is rated at 400kgs. To compliment the setup, S3i 316 Marine Grade Stainless Steel Eyebolts, Turnbuckles and Hardware finish the project.

This is an ideal antenna for enthusiasts interested in ‘FM Dxing’. Whilst manufactured primarily as a receive antenna, the use of premium Vortex hardware will enable the unit to be used in ‘TX’ (license permitting) up 1kw power levels. Users have the option to also have an SO239 coax connector installed or to use M5 stainless machine bolts for a balanced line feed.

Antenna is supplied with all hardware except boom to mast mount (see below).

All VORTEX Antennas can be shipped WITHOUT any boom to mast mounting plates. Select this option from the drop-down menu when purchasing. Other options include the choice of mounting plates and complete mounting solutions with U-Bolts and Brackets.

See info below for mechanical and electrical details
*When available

This is what one of our buyers said about the 7 element version of this antenna:
Steve – I’ve been into radio for over 50 years and in that time had many many aerials, but when I received the Vortex LPA FM antenna I was really taken back by the build quality (Just Amazing), it’s not just an aerial – it’s an engineering masterpiece. I may be old in my ideas but I think the better you make an aerial the better it will perform, and this Vortex proves my point. I’ve been using a Triax 8 element at 40 feet, not a bad antenna – DX all over Europe and many hard to receive community FM stations in UK. The day I fitted the Vortex on the wind up mast it was very windy and in lowering it unbeknown to me at the time, I had bent the last section of the mast, so when the LPA was fitted the max height was 25 feet, so the results are at 25 feet being compared to 40 feet with the Triax 8. The very first thing was the gain was up 1 S point and that is right across the band 87.5 to 108MHz. The other amazing thing was the dynamics of music had increased and by not a small amount in fact on a BBC live broadcast the sound quality is the best I’ve ever heard on FM radio ever – it was simply stunning. DXing with this antenna is a dream. I’ve only had it a week and logged 1 new station and this with the antenna at only 25 feet. My receivers are = Revox B760, Revox B261, Sansui TU9900, Onkyo T9900. If you’re looking for the best FM aerial ever made you have now found it – AND IT’S MADE IN THE UK. Mike Wallis – Nottinghamshire,UK

See info below for mechanical and electrical details

  13 Element Log Periodic Antenna (Lightweight) – 88-108MHz

Band(s):  Band II (88-108MHz)
Element Material:  6082-T6/*AA6082-T6
Boom Material:  6082-T6 box section aluminium
Boom Length:  6.00m
Gain:   18.87dbi for the lower end of the band reducing to 10.42dbi at 106MHz
Front to Back Ratio:   Typical over 25 db, max 42.79db at 102Mhz
Feed:   Via SO239 Socket or stainless M5 machine screws
Matching:   None – direct connection
Rating:   For RX only but will handle 1kw in a licensed TX situation
Element Clamps:   Stauff (Germany) – standard duty polyamide series
Antenna Weight:   15kg
Impedance:   50/75 ohms
Longest Element Length:   1.82m
Hardware:   304/316 stainless steel

*If available