991-A wideband mod

I am considering getting a Yaesu 991-a and having the wideband modification so I can also use it on 11m.  I would use it as a base radio and keep my Lincoln 2+ for mobile use. Does anybody have any experience of this and is it reliable. I don’t want to spend £1k plus and regret it. 

Thanks,
Martin (26CT4995)

Hi Martin,

I have the wideband mod done on my Yaesu 450d. Mine was done by the dealer ML&S who I bought the radio off.

Yes it definitely works reliably but there are a couple of issues to consider. Firstly the filters in the radio will not be designed for the 11 meter band so don't run it flat out in FM mode, SSB should be fine. You may devalue the radio because it's target market radio amateurs may not want to buy it with the mod having been done.

In all honesty I mainly use my radio on the amateur bands so in a way I wish I hadn't bothered doing it.

Best 73 Gary.

Thanks Gary, I will certainly think carefully before making a decision and weigh up the pros and cons. As my Lincoln is already expanded I might lean towards not having the mod done and just use the 991a for the amateur bands only.

Cheers,
Martin

The filter 'issue' with wide-banding amateur radio gear used to be true on some older units with filters present for each of the amateur bands only. Nowadays the band-pass filters etc. are much wider than they used to be making the circuitry less complex (cheaper) and more frequency agile.

In the Yaesu FT450 that Gary mentions the band pass filter (BPF7 in the circuitry) runs from 21.5 to 33MHz so there is no issue there. Similarly the PA filter in that group runs from 24 to 28MHz so the CB frequencies happily sit within range.

On the Yaesu FT991a the band pass filter for that group runs from 20.9 to 30MHz so again no issue when wide-banding such radios.

However, as Gary also points out utilising FM mode means that you are running a 100% modulation process which can push the PA transistors very hard (flat out!) so worth dialing back a little bit. This again used to be more of an issue with older radios and not so much with modern PA devices.

I'd happily run a modern radio that was wide-banded based on modern specifications.  

The re-sale value can be a flip of both sides of the coin.....I wouldn't want to buy an expensive rig that someones 'fiddled' with but happy if a supplier performed the modifications.

Then there is the 'legal' aspect that we all know and love in that a piece of equipment designed for amateur radio frequencies would no longer be 'compliant' if modified for CB frequencies. A similar tale is true for CB radios that have been 'expanded' or capable of SSB/AM transmission on the UK frequencies etc.

You take your own chances really.


FWIW I have the Yaesu FT450 also and it would be a breeze for me to modify it but I'd rather keep it as originally designed. Luckily I have other radios that can accommodate CB frequencies so I use them instead.

(But when Ham gear can turn up just as cheap as some 'classic' CB radios it's a no-brainer really especially with advanced features not found on CB equipment!)


Apologies for the 'waffle' but hope that helps not only you but others reading that may be contemplating similar.

All the best,
Victor

My tuppence worth...
I bought my FT857 from a G1 ham that had the radio widebanded from the supplier because he had an NoV for 60m (5Mhz) but of course it will now TX from 1.8 - 54, 137 - 164 & 420- 470Mhz so will work on CB, PMR446 and marine band as well as the normal ham bands, if I wanted it to. However, I mostly use it on 2m for GB3EM, and odd times listen to PMR ch13 (some locals use it for chit chat, naughty naughty), but just because it can, doesn't mean it does.

I much prefer my old 80's CB's (with an amp when needed) for 27Mhz because it's 'proper', at least for me anyway. Yes some folks use ham radios for CB (IC7300 is favourite apparently), just not for me, but then I'm an OAP now lol, it's a nostalgia thing. If a radio isn't widebanded it can always be done at a later date if needed (though better to have it done by the shop for warranty purposes). To do it or not is a personal choice, but most ham radios can listen to CB anyway, even if they can't TX there. Personally I'm not so interested in HF tbh, just CB.

Thanks all for your responses and advice. I think I will leave the 991a as standard as I wouldn’t want to take the risk, however small, of damaging it and also it’s a good reason to buy more radios for different bands/uses

Cheers,
Martin

Hi Martin. I'm a bit late to respond as looks you've made a decision already, and probably made a good choice, so take my notes as and if you wish...

Mine was done by the shop when bought new 17 months ago. All is still well with it. It's mostly used for ham bands though as have other equipment for 11m.

The mod that was done to mine is the standard fairly simple mod that the instructions to do can be found in many places on the net including videos. That opens up most of the HF frequencies, but does not wideband the VHF and UHF sections. If you had any thoughts on making a PMR446 powerhouse you would need to do further work on it.. there are a number of ways to do this, but please don't.. the few power houses around here swamp our little legal PMR units a number channels either side when they key up.