The Forgotten FB5 Ham Radio Antenna - | HF Antennas

[@rogerlafrance6355]

I think it would be interesting to try beads on a EFHW to reduce multi lobes on the high end and perhaps lower the low end. Getting best performance on all bands, with one antenna, is still a goal. Also, Lazy H and Serba Curtains are a good solution to lower the radiation angle at low antenna heights.

[@TVPiles]

For the beads I suggest free hanging ~300 ohm beads. What I am still working on is finding the ideal number and spacing of the beads. Regards, KE0WST.

[@crosscountrywireless]

Thanks, Peter, for the video about a G4ZU antenna I hadn't heard of before. Rather than try to find the Mullard ferrite bead info (I tried!) consider the design as usung inductive loading to resonate as a half wave dipole on 80m. with the bead position allowing a match on 40m and above as you say in the video. You could use small multi-turn inductors on say T50-6 toriods which will have lower RF loss than the original ferrite beads. I'm moving up to Scotland next week so I'll try building this design once we are settled in. 73 Chris G4HYG (GM4HYG)

[@watersstanton]

OK keep us informed on the resulrs.

[@G7VFY]

How many turns do you think you'd need? I guess they will need to be potted to protect them, and some kind of strain relief? G7VFY

[@crosscountrywireless]

I'm not sure of the number of turns yet but both inductors could be mounted inside a junction box at the centre of the dipole with the ribbon feeder cable. 73, Chris GM4HYG

[@basshorseman998]

Thank you Peter, another very interesting video that keeps me thinking...I have indeed used a few of your ideas to great success...stay well

[@watersstanton]

Cool, thanks

[@davidwalle5025]

Very good video i need to research this antenna more it may a good application for my station. Do more videos like this.

[@watersstanton]

Glad it was helpful!

[@clivedavies3]

Interesting might have to have a play with this one.

[@9ernie9]

I found reference to the antenna in Short Wave Magazine March 1969 and it refers to 25 Type B4 Mullard FX1308. I have a Mullard data book (1978/79) but unfortunately it doesn't list the 1308.

[@watersstanton]

Yes I could not find the spec.

[@tlebryk]

Great idea to experiment with on any antenna! ❤

[@KingLoopie1]

Homemade antennae are half the fun! Trade you some rain for some of Colorado's hot and dry... 😏

[@johnharrison373]

Very happy to trade 🌧 for ☀️👍

[@arcticradio]

I’m in need of Long Wave antenna help on a smaller 1/4 wave scale. If you have any time I would love to hear if you have knowledge of setting up something on this scale.

[@petermainwaringsx]

The G5RV is the same age as me too Pete.

[@KL3NCH]

Look in Dennis Hoult's (G3OO?) book published by the Spalding and District ARS!

[@paularndt4585]

Danke für die gute Erklärung, ich habe solche eine Antenen und werde sie alsbald aktivieren

[@watersstanton]

Many thanks.

[@dezwatson6993]

The forgotten FB5 antennas' dimensions are not too dissimilar to what you would get if you built a 14 MHz Extended Double Zepp (EDZ). A vertical section of 450 ohm balanced line can be used on the EDZ too to provide a good match to 50 ohm coax so it's worth experimenting with the FB5. The short vertical section on the EDZ also results in a tighter main lobe. The main lobe would indeed start to break up if the balanced line was omitted and the missing 10 foot were added to the horizontal elements. Ideally you want to try to keep the horizontal elements no greater than 5/8 wave long on the main design band. I'll definitely try a FB5 if the wx picks up! 73 Dez, G3WW.

[@watersstanton]

Many thanks for that info. Let me know how you get on with the antenna.

[@pauls8456]

Whilst in the UK I met a ham who knew G5RV - it was never intended for the wide band use it sees today…..

[@watersstanton]

Agreed

[@johnhess351]

Very Interesting. Especially intriguing on how 10 beads can work and 25 beads works better. I would guess that more beads increases Q (useful Z?) on the higher bands and achieves higher gain while 10 beads (spaced?) can get you into the realm of acceptable efficiency with those same harmonic bands? The wide range of numbers of beads that are said to achieve working results tells me that the specific specification of the the bead used may not be absolutely essential to get proper performance. If you used the wrong bead, or even mixed beads, you might have to use a few more. At some point in experimentation it would be obvious that adding more beads is not improving. 'think I'll try the double for fun when my new sino analyzers get here, but how does 80 take care of itself?

[@MINI-4X4-RADIO]

70's... The "Joy Stick" Antenna... Ooh er missus

[@jerryKB2GCG]

Fine Business 5? 😊

[@teslar1]

Here’s what Chat GPT could tell me with a bit of prompting Thank you for the clarification. The FB5 antenna designed by Gordon Bird (G4ZU) indeed uses a unique design involving ferrite beads to create a multi-band dipole. This antenna employs a specific arrangement of ferrite beads along the radiator elements to manipulate resonance points. Here are the accurate details for the FB5 antenna: ### FB5 Antenna Specifications 1. **Antenna Type**: Multi-band Dipole 2. **Design Principle**: The FB5 antenna uses ferrite beads placed at intervals along the dipole elements. These beads act as chokes at specific frequencies, effectively creating multiple resonance points along the length of the antenna. This allows the antenna to operate efficiently on multiple HF bands without requiring complex matching or multiple elements. 3. **Construction**: - **Elements**: The dipole consists of two radiating elements. The lengths of these elements are chosen based on the desired bands of operation. - **Ferrite Beads**: Ferrite beads are strategically placed along the elements. The exact spacing and number of beads depend on the specific design and the desired frequency bands. 4. **Bands Covered**: Typically designed to operate on several HF bands such as 80m, 40m, 20m, 15m, and 10m. 5. **Impedance Matching**: Standard dipole feed point impedance matching techniques are used, often involving a balun (balanced to unbalanced transformer) at the feed point to match the balanced dipole to the unbalanced coaxial feed line. 6. **Installation**: Similar to other dipoles, the FB5 can be installed in various configurations like horizontal, inverted-V, or as a sloper, depending on the available space and desired radiation pattern. ### Practical Considerations - **Ferrite Beads Selection**: The type and material of ferrite beads are crucial. The beads need to be effective at the specific frequencies of interest, typically involving materials like type 43 or 61 ferrite which are common in HF applications. - **Element Lengths**: The lengths of the dipole elements need to be calculated considering the presence of ferrite beads, which influence the effective electrical length of the antenna. ### Additional Resources To build an FB5 antenna or understand its detailed design, you might want to consult specific articles or publications by Gordon Bird (G4ZU) or resources shared by other amateur radio enthusiasts who have built and used this antenna. Forums, antenna handbooks, and specific articles in amateur radio magazines often provide practical insights and detailed construction guidelines for such antennas. By looking into these resources, you can find detailed instructions, diagrams, and tips from other builders, which can help you successfully construct and deploy an FB5 antenna for your amateur radio operations.

[@watersstanton]

Thanks for the info. The arrangement and critical position of the beads you outline is at odds with G4ZU published data. The beads do not act as chokes. They add inductance. In fact as I said in the video, G4ZU suggested that even less beads can still work.

[@teslar1]

@@watersstanton that’s ChatGPT for you. It hallucinates a lot 😂

[@crosscountrywireless]

Ome point to condider is that the early ferrite materials made low loss inductors at HF frequencies. As modern ferrite materials are now used more for EMI supression, far lossier materials are used having the side effect of widening the supression frequency range. The FX1300 ferrite used was a very early version not included in the later Mullard catalogue someone posted on the internet. 43 material beads may work but will be lossy. 73, Chris GM4HYG

[@dennispeake1877]

Peter G'day mate, I'm very interested in HF antenna and enjoy your talks , your asking type of Ferrite Beads to use , type 43 is the normal ones. Cheers . I really enjoy your videos .

[@TheGazLab]

Really interesting video Peter, I love some those old designs, another one was the folded dipole was it T2FD? I made a few some time back installed at 30deg to a single point.. a good friend (now silent key) was the brains of the outfit 🙂gave me a lot of information long forgotten!! would love to hear what you know about the design.. all the best.. Gaz

[@watersstanton]

Many thanks.

[@Rubedo777]

Hhmmm wish I had a garden big enough to experiment in… my “garden” is 6m x 4m but… I’m working on a stealth doublet running around the plastic gutter of the house and along the fence raised on small wooden poles… one leg goes over the pavement to a limb of a tree about 4m ish high so it won’t strangle anyone… I’ll have to do a ninja and put it up when twilight comes and everyone is watching telly… 😵‍💫 🤣…. If it works,,, then I’m back after a hiatus since 1996… This antenna you describe in the video would be heavy don’t you think with the ferrite beads on ? but dickie bird must have been a clever chap with his designs. 🧐 🤔 Best wishes to everyone.73. 💙

[@watersstanton]

Thanks for sharing, Ferrite beads are very light. so weight would not be a problem.

[@andye2005]

Yes agreed, a classic problem is that many (most?) people do not know what a small garden is. A garden that can hold an 80ft + antenna is a HUGE garden. Andy

[@JH-jp9sv]

Fine Business 5 bands.

[@ianliston-smith7921]

Antenna modelling anyone?