Zetagi MM27 Matcher

Please can anyone tell me the actual tuning range of these? I know they’re advertised as 26-28 MHz.

I’m using a 27Mhz T2LT that also tunes perfectly to way up in the 10 Metre Band with the help of an old Bremi BRL-15 matcher. Unfortunately it doesn’t work to tune the antenna down to 12 Metres, giving a SWR of about 2:1 on 24950.  So just wondering if a £25 outlay will get me operating on 12!

Cheers,

G0DNV/26CT3352

Hi John. I can't confirm the tuning range of this matcher, sorry, as haven't used. But would like to suggest that, unless you are going to use big power, that you don't worry too much about a 2:1 SWR. My 10/11m fan dipole element has that same SWR when I go down to 12m, but it's working fine, worked 4 continents on 12m in the last few months, and the rig doesn't complain... it doesn't start dialling back the output power until it hits 3:1.

Thanks for the reply.
Unfortunately I’m running a IC 703 into a KL-203 linear (with a LPF after it before anyone asks) so I’m concerned about magic smoke from the amplifier. 
Probably with a SWR about  2:1 I’d get away with it on a ‘5/9 73s’ QSO, but maybe a decent ragchew would cause problems.
I’ve had the 203 since I returned to the bands a couple of years ago, and it works quite well,  but never run it over over about 1:5

A better antenna can work wonders.
Sorry to say that but trying to run power through a badly matched antenna will never have a good ending.

Alan Pilot wrote:

A better antenna can work wonders.
Sorry to say that but trying to run power through a badly matched antenna will never have a good ending.

I don’t need and wasn’t asking for a lesson in antenna theory, I’m asking a question about a matcher…

I've had a jolly good search around the net this morning to see if anyone has used one on 12m. Not a sausage. Not even details of any other older Zetagi matchers being used on 12m. If no one else has tried, or can't find any documented info on the range, for the relatively low price (for radio equipment) I would buy one and give it a try. I am sure others would find your results useful in the future. Could always sell it/swap it if it doesn't do the job.

12m has been hotting up in recent weeks, hope you can get yourself on there.

Don't take this the wrong way.
I like Neal have googled it and found nothing too but as it is made for cb then i don't think many would have tried it on a ham band.
Also as he said worth buying one at the price to try but i don't understand why on 12m.

Hi John,

CB accessories such as this are usually specified around 27MHz the manufacturer allowing for the roll-off hence advertised as 26-28MHz. In fact they tend to be centered around 27.5Mhz so will tune slightly higher than advertised but usually not lower. (It's more to do with impedance than anything designed to match the expected resonance of an 11m antenna and allowing a 'tweak' for variance.)

This is what you found out with the Bremi BRL-15 managing up to 10m but not down to 12m.


The Zetagi MM27 is a similar unit to the Bremi's with a couple of polyvaricon variable capacitors but rather than a spiral inductor etched onto the PCB (Bremi) they have a proper coil mounted to the board. You can open these units up and slightly 'stretch' the coil physically to reduce the 'frequency' but then you may find that you can't tune up to 10m afterwards(!)

To match the impedance range you are expecting from a single antenna will require a bit more work.

There's an article in the following link that shows how someone managed to expand the range of a Bremi unit to cover HF bands by replacing the PCB etched spiral coil with a hand wound coil if it's helpful at all :-

https://rsars.files.wordpress.com/2013/01/bremi-brl-ant-matcher-hf1.pdf


But in answer to your question I'd think the Zetagi will perform similarly to the Bremi you already tried.


I'd personally avoid units that utilise cheap polyvaricon capacitors for anything but QRP levels myself as I've seen too many others experience problems with arcing RF.


Hope that helps.

All the best,
Victor

Alan Pilot wrote:

Don't take this the wrong way.
I like Neal have googled it and found nothing too but as it is made for cb then i don't think many would have tried it on a ham band.
Also as he said worth buying one at the price to try but i don't understand why on 12m.

Ok Alan, no problem.

I can use 12 Metres on my FT-817 with the MX-P50M 35 watt amplifier on 80 -10 with a end fed multi band wire which does work quite well, but on 10 & 11  I have better results with my IC 703 and KL203 into the T2LT.
  I keep toying with the idea of a beam again for 10 Metres, but do like the challenge of running with the vertical.
As mentioned the T2LT won’t  tune down to 12 Metres with the little Bremi, but if the Zetagi won’t do it either I still have the first option with the FT-817 set up.

Yes, maybe I’ll run to the expense of flashing out 25 quid out of my pension for the MM27, at least It’ll be back up for the Bremi!

Victor wrote:

Hi John,

CB accessories such as this are usually specified around 27MHz the manufacturer allowing for the roll-off hence advertised as 26-28MHz. In fact they tend to be centered around 27.5Mhz so will tune slightly higher than advertised but usually not lower. (It's more to do with impedance than anything designed to match the expected resonance of an 11m antenna and allowing a 'tweak' for variance.)

This is what you found out with the Bremi BRL-15 managing up to 10m but not down to 12m.


The Zetagi MM27 is a similar unit to the Bremi's with a couple of polyvaricon variable capacitors but rather than a spiral inductor etched onto the PCB (Bremi) they have a proper coil mounted to the board. You can open these units up and slightly 'stretch' the coil physically to reduce the 'frequency' but then you may find that you can't tune up to 10m afterwards(!)

To match the impedance range you are expecting from a single antenna will require a bit more work.

There's an article in the following link that shows how someone managed to expand the range of a Bremi unit to cover HF bands by replacing the PCB etched spiral coil with a hand wound coil if it's helpful at all :-

https://rsars.files.wordpress.com/2013/01/bremi-brl-ant-matcher-hf1.pdf


But in answer to your question I'd think the Zetagi will perform similarly to the Bremi you already tried.


I'd personally avoid units that utilise cheap polyvaricon capacitors for anything but QRP levels myself as I've seen too many others experience problems with arcing RF.


Hope that helps.

All the best,
Victor

Thanks for the information, I was wondering why the Bremi wouldn’t tune down very far.
Unfortunately my mods days are over, due to my problem with Episodic Ataxia which means my hands shake too much for intricate work,but as long as I can key the mic and lift a pint glass I don’t complain or moan about my ailments too much!

No worries there John.

For £25 it might be worth getting the Zetagi, attempt to stretch out the coil even with a little help from someone so between that and the Bremi you'd get the coverage you need.

You keep keying that mic and lifting the odd pint or two mate.  


All the best,
Victor

Victor wrote:

No worries there John.

For £25 it might be worth getting the Zetagi, attempt to stretch out the coil even with a little help from someone so between that and the Bremi you'd get the coverage you need.

You keep keying that mic and lifting the odd pint or two mate.  


All the best,
Victor

A £22.99 (free postage & cheapest I could find ) MM27 arrived this morning.
 Doesn’t tune at all above 28100, . But very surprisingly without even opening the case it tunes perfectly on 24950!
Thanks again for the advice & HNY

73 de G0DNV

Hi John,

Fantastic news to hear mate and well done!  

Very glad that it worked out well straight from the box and what a bargain price to gain another band.
This will all be good news as well for other readers of your posting so a big thumbs up and a 'Thanks' to you from me.
(Excellent feedback on your enquiries and purchase. )

Great start to a Happy New Year for yourself.


Take good care and enjoy your radio work.

73 de M7VIC