I will spend some time to improve the set up and try a different PSU and Coax. However it comes down to the question : Are these small amps worth the hassle id they degrade the audio. i am thinking that its prob not.
Deffo worth the hassle Fred, with a little bit of tinkering I'm sure the amp will spring back to life. If it's not blowing fuses, then it may just need the right psu and input power and audio levels. Saying that I am a radio ham, a radio hoarder and starting to amass a bit of a shack again. I don't like to throw stuff away, a case of fix it or use it for spares. :)
These linears always done this back in the day (i had the same one once) and only remedied when i finally opted for a valve amp - also Zetagi. SSB was crystal clear.
I just bought the RM Italy KL 503 HD and I'm having the same problem as well. these amps suck in ssb. they sound good in AM, I haven't tried FM yet. Thanks for a great video
Hi Fred. Interesting vid as usual. I agree that it’s your audio quality that makes you heard and makes the trip. Unfortunately many people don’t realise that you can be giving a 9 signal yet can’t be heard. Also when they come off side band they don’t turn the watts off on standard uk 40! I use 4watts on am/Fm and 12 on legal ssb and get out pretty well. CB after all was short range communication for the public. I suggest people get the Ham license if they want to go for distance and do the job properly and know what they are doing! 👀
I like antenna switches with a solid metal mechanism. I tried a cheap workman antenna switch and inside it was a switch with wireing and certainly not 50ohm wireing! And it actually caused my swr to rise slightly and even more with the linear on. So in the bin it went.
Audio of clipping due to lack of power to the amp. It’s exactly the same with car audio. The speaker will clip if the power supply isn’t providing it good enough. Great video as always Fred !
I have two transistor amps and one tube amp and I use neither. They worked OK but I grew out of the amplifier stage and use all stock power. My main issue was there was no real way to tell if you were over-driven in audio or just putting out a nasty loud signal. The linears do work well but you really need to be cautious as to how you set them up and how you use them. Power input needs to be adjusted differently for each radio. SWR is also an issue in higher watt outputs. Hooking up the amp wrong can be very brutal on the radio and cause amp failure. There are just so many things that can go wrong and really it takes a lot of expensive power and clean expensive power to make a real difference especially in regards to DX. Most stock radios will work well when proper conditions are on the go. So, yeah, they can be fun and work reasonably well but I just grew out of it before it became a necessary component to me. Some folks swear by them and never run stock power ever. A good neighbor keeps his/her splatter to a minimum as well. Another issue to contend with as well. I am done rambling now. Thanks for the video Fred. All the best my friend.
I would not have the amp so fare from the radio and minimum 25amps to run the amp. and of course of your mic audio, Nice rigs, Cheers for Menifee,California
Fred your psu not man enough for your amplifier 9w into 150w pep ssb or more like 80w fm from the amplifier you need 30amps or 40 amps plus your 14v is driving the amplifier mosfets at maximum motorrola 70w mosfets pair the amplifier power lead too carry the current remember how thick a 100w transceiver is if you open the amplifier check the fuse and the fuse rail on the circuit board for heat damage and around the mosfets remember its only the heatsink for cooling especially in it life before you might of had long key downs and over driven they generate lots of heat they are wonderful if used right and help if your marginal signal only 6db increase half a db not even noticeable on a s meter but noticeable on your audio not bad for 1w or 10w pep from your rig too the amplifier great station you have and passion keep it going best 73s best dx de 2E1DNC mike
Hi Fred, I had one of those cheap switches and it became useless as the switch got worn and wouldn't change over properly. I now have a alpha Delta 4b which is brilliant it grounds everything when you switch off and is has surge protection only problem it's expensive but worth it. 73's Alan CT2661
I think turning the rf power up into the amp would help, on sidebands on the 9900 I would have the rf power knob at 12 oclock, so about half way round to give that amp about 10w, I think you are actually underdriving it. I think with the mic gain at 10 you aren't even triggering the amp at all, with it turned up you are starting to see the relay clicking on and off as you just drive it with the loudest parts of your audio. If you turn up the rf power then the mic gain will be irrelevant. I found this with my kl203p and the 9900 - 108DR358 - till the next time on the radio my friend - hope you get it sorted
Good video Fred, were you able to check the power out of the amp to see what its pushing out. Im wondering if the psu is not man enough and the amp is drawing too much current, possibly then causing voltage drops to the amp which appears as clipping? Can you measure the amps psu voltage to see if its dropping to lower levels on TX? Keep up with the great work :) Have you got a low pass filter after the amp, cos if youre clipping you may be giving out spurious noise further up the bands, save a visit from the 'man from the ministry' :) 73 Cclin
fredintheshed1 one other thing to check Fred is if jt has an FM/SSB switch on the amp, try both those modes in conjunction with the modes on the radio and try it again at full power, then see if the clipping occurs in both modes. With the FM mode, the amp should run as a Class C amp with little to no transistor bias, any clipping shouldn't effect the FM modulation. In SSB mode the amp should run as a Class A or AB amp and use little transistor biasing to keep the output signal linear. Perhaps this biasing is off and appears at higher input levels, or the voltage supply is affecting this bias and killing the signal linearity, hence distortion or clipping? Just a wild thought, hope it helps some :)
Thanks Colin some very useful advice. Just what i needed and i will be running some testing in the future. Video's tend to be around 3 weeks behind so look out for it.
Hi Fred, always glad to help where and if I can :) I'm looking forward to see and hear how you get on. I did a bit of digging and found this link to the Nevada Radio site, with the specs for this Amp: www.nevadaradio.co.uk/amateur-radio/amateur-radio-amplifiers/zetagi-b-150p Longish thread alert... :) This link above shows the amp input power between 0.5w and 5w to achieve the power out (60-100w for AM/120-200w for SSB). However a few calculations of you PSU, with Power = Voltage x Current, your input power = 13.8v x 15amps = 207w. This 207w is all you have as a maximum to feed the amp. Using the same calculation of P = V x I, therefor I = P/V, the B150 Amp needs a certain amount of current to produce the 150w using 13.8v. The current needed (using I = P/V) is 150/13.8 = 10.8amps. However this assumes the amp is 100% efficient. With Class C amps, FM mode, you get around 60% efficiency and with Class A amps (SSB mode) you get less at between 30-40% efficiency. This lack of efficiency is lost as wasted power output in the form of heat. To get more power, then more current is needed as the 13.8v input voltage is constant. The issue here is then you may need to drive the amp a little harder with more drive power, but this in turn forces the amp to require more current. As it requires more current, possibly more than the psu can provide, the psu output drops, with this drop is a possible drop in amp biasing voltages and makes the amp work in less linear modes, hence the distortion. Anyhoo,. sorry for the lecture, apologies if I'm teaching you to suck eggs here :)
Thanks again Colin. Interesting stats. I think i will revisit this issue in a few videos time. First job is to replace the RG58 with better RG8. Make a new patch lead and try a 30 amp supply. I will see how that goes.
I got the b-150 for a good 20 years. Has got the mrf455 as final? The amp without relay if I'm right .But if I remember it right it was for fm/am only. I have tried to use it in the past on ssb but it sounded just horrible ... must have got the original folder somewhere ,and I believe it says it there... and that was mobile , so no dc power shortage .
I had a B150 before which i used on my Grant 2 and that one worked fine. I spent all summer getting out on 20 watts with the 6900N. Iam not sure you need any more.
Make your box with C or N connectors. I KNOW it's hard on RG8 or H100 - but if it's over 15 metres it's worthwhile, The connectors are impedance neutral, 259s are not :)
It's sounds crap because there's no filtering in them. If you put a band pass filter on the output it will clean your audio up and stop the shite (harmonics) coming out of it!!!!!!
Your 9900 dont have a power killer right? You can t use the mic gain as a power killer I think..... Don 't drive I much harder than 4 watt s it won t hurt the zetagi, but your power settings on the radio should be adjustable for this.....
Ask someone the question and you will get a different answer ever time :-) Myself i like 213 as it as tough as old boots and low loss. its reasonable priced as well.
Interesting freedom of information response from OC regarding the use of linear amps. Basically, they don’t care: www.whatdotheyknow.com/request/illegal_use_of_linear_amplifiers
I think its just they no longer have the resource available. The lines "Accordingly it is not considered to be a proportionate use of resources or otherwise in the public interest to investigate your complaint." sums it up. It will be the same with people using HF radios on 11 m.
Fred in the Shed indeed. My local planing dept. now says bluntly on their website and downloadable guide: unless a suspected breach is causing you direct harm, don’t contact us, as we don’t have the resources available to chase up minor issues. Good days for antennas.....
The amp sounds crap because it's not getting enough current from that feeble psu . I suffer from the same problem when my leisure battery bank starts to go flat when I'm portable .
YOU DON T NEED THE RF AMLIFIER!!!!!!! YOU NEED KNOWLEGE FOR OLD IT IS ABOUT TRANSMITTING AND HEARING GOOD AND TAKE IT MASURES FOR COAX FOR FREGUENCY TO YOU WAND IT!!!!!!
Woah LOL. No need to SHOUT. Your not making an awful lot of sense to be honest but i think i catch your drift and, well i guess thanks for taking the time to comment on the video. 73
Anytime I have messed around with mobile linear amps in the past they've nearly always caused complications. The only exceptions have been home based ones with a plate and load on them. Added to the things that can go wrong, you have also got all of the connections and wiring all over the shop :D My next radio will be a HF set. I'm completely disillusioned by the quality of these Chinese export style radios and for the price you can almost pick up a second hand HF radio. There's no comparison to these ssb chicken boxes :P
That would actually make an interesting video you could make m8. Comparing the reception side by side of your Alinco, Yaesu 450D, SS9900, SS6900 and your hf receiver. I find my SS6900 receives very poorly indeed.
The receive on the SS9900 is pretty good to be fair. I would say on 11 meters it can match what i get on HF gear. The transmit is a whole different story. I am going to do a video with CT2865 and he will run a 6900, 9900 and then a Yaesu 991a. The 991a audio is in another world.
To be fair the receive on the 6900 is fine as long as i dont get signals lower than 3-4 and then everyone goes very very quiet. Other than that it's just very noisy even on AM and SSB. The front end overloads on SSB if I'm talking to very local people, but that's not a problem cause dx by it's definition is not local. :D With some work ( mods to the basic radio ) it would be a fine radio indeed. It's just not worth spending the money on it.
Развлечения
I will spend some time to improve the set up and try a different PSU and Coax. However it comes down to the question : Are these small amps worth the hassle id they degrade the audio. i am thinking that its prob not.
Deffo worth the hassle Fred, with a little bit of tinkering I'm sure the amp will spring back to life. If it's not blowing fuses, then it may just need the right psu and input power and audio levels. Saying that I am a radio ham, a radio hoarder and starting to amass a bit of a shack again. I don't like to throw stuff away, a case of fix it or use it for spares. :)
These linears always done this back in the day (i had the same one once) and only remedied when i finally opted for a valve amp - also Zetagi. SSB was crystal clear.
I know is video a year old but if that amps class c it only for am n fm not ssb n 2 watts dead key all you put in these or rm
Ab1 is whut need for ssb
I just bought the RM Italy KL 503 HD and I'm having the same problem as well. these amps suck in ssb. they sound good in AM, I haven't tried FM yet. Thanks for a great video
RFC 240 UF COAX I love the videos Fed thanks for making them
And I LOVE your little shed!!!!
Its where things started 6 years ago.
Great video Fred. Not to mention the plethora of interesting comments. Thanks Fred. Take care.
Thanks Roy.
Hi Fred. Interesting vid as usual. I agree that it’s your audio quality that makes you heard and makes the trip. Unfortunately many people don’t realise that you can be giving a 9 signal yet can’t be heard. Also when they come off side band they don’t turn the watts off on standard uk 40!
I use 4watts on am/Fm and 12 on legal ssb and get out pretty well. CB after all was short range communication for the public. I suggest people get the Ham license if they want to go for distance and do the job properly and know what they are doing! 👀
Having a older uniden 76xl redone, but had variable power and a improved 100w kicker. Im in Oregon.
Great film as usual, by the way :)
I like antenna switches with a solid metal mechanism. I tried a cheap workman antenna switch and inside it was a switch with wireing and certainly not 50ohm wireing! And it actually caused my swr to rise slightly and even more with the linear on. So in the bin it went.
Shame it went in the bin .. would love to have had a go at upcycling 😊 73's
Great content 👌🏽
Audio of clipping due to lack of power to the amp. It’s exactly the same with car audio. The speaker will clip if the power supply isn’t providing it good enough. Great video as always Fred !
Thanks Sam. Its one of the things i will look at when i cont with this little project.
Thanks
I have two transistor amps and one tube amp and I use neither. They worked OK but I grew out of the amplifier stage and use all stock power. My main issue was there was no real way to tell if you were over-driven in audio or just putting out a nasty loud signal. The linears do work well but you really need to be cautious as to how you set them up and how you use them. Power input needs to be adjusted differently for each radio. SWR is also an issue in higher watt outputs. Hooking up the amp wrong can be very brutal on the radio and cause amp failure.
There are just so many things that can go wrong and really it takes a lot of expensive power and clean expensive power to make a real difference especially in regards to DX. Most stock radios will work well when proper conditions are on the go.
So, yeah, they can be fun and work reasonably well but I just grew out of it before it became a necessary component to me. Some folks swear by them and never run stock power ever. A good neighbor keeps his/her splatter to a minimum as well. Another issue to contend with as well. I am done rambling now. Thanks for the video Fred. All the best my friend.
Cheers Andy. Setting up these small amps is tricky and demands some skill. However is it really worth it.
I would not have the amp so fare from the radio and minimum 25amps to run the amp. and of course of your mic audio, Nice rigs, Cheers for Menifee,California
Fred your psu not man enough for your amplifier 9w into 150w pep ssb or more like 80w fm from the amplifier you need 30amps or 40 amps plus your 14v is driving the amplifier mosfets at maximum motorrola 70w mosfets pair the amplifier power lead too carry the current remember how thick a 100w transceiver is if you open the amplifier check the fuse and the fuse rail on the circuit board for heat damage and around the mosfets remember its only the heatsink for cooling especially in it life before you might of had long key downs and over driven they generate lots of heat they are wonderful if used right and help if your marginal signal only 6db increase half a db not even noticeable on a s meter but noticeable on your audio not bad for 1w or 10w pep from your rig too the amplifier great station you have and passion keep it going best 73s best dx de 2E1DNC mike
You may want to try some RG 213 coax or some lmr400
Don't worry about burners get that satellite dish sorted out
LOL it actually still works but i dont really use it. It does look a mess.
Hi Fred,
I had one of those cheap switches and it became useless as the switch got worn and wouldn't change over properly.
I now have a alpha Delta 4b which is brilliant it grounds everything when you switch off and is has surge protection only problem it's expensive but worth it.
73's Alan CT2661
Thanks Alan i will check out the alpha 4B.
It looks good. Mind you at £110 delivered your right it is pricey. Prob too much to leave in the shed .I might better with simple barrel connectors.
Fred, I’ve seen these Amps working very well on FM.
SSB being PEP can be problematic though.
Yes i agree. The larger ones work better.
Nice one Fred its all good fun matey great vid speak soon CT2865
Thanks for the testing Dave. Have a good weekend away
I think turning the rf power up into the amp would help, on sidebands on the 9900 I would have the rf power knob at 12 oclock, so about half way round to give that amp about 10w, I think you are actually underdriving it. I think with the mic gain at 10 you aren't even triggering the amp at all, with it turned up you are starting to see the relay clicking on and off as you just drive it with the loudest parts of your audio. If you turn up the rf power then the mic gain will be irrelevant. I found this with my kl203p and the 9900 - 108DR358 - till the next time on the radio my friend - hope you get it sorted
Thanks Liam. Others have also said more power into the amp. I think 12 oclock may be a bit strong but i can put a meter on it. Cheers for the help.
fredintheshed1 did you get it sorted?
Good video Fred, were you able to check the power out of the amp to see what its pushing out. Im wondering if the psu is not man enough and the amp is drawing too much current, possibly then causing voltage drops to the amp which appears as clipping? Can you measure the amps psu voltage to see if its dropping to lower levels on TX?
Keep up with the great work :) Have you got a low pass filter after the amp, cos if youre clipping you may be giving out spurious noise further up the bands, save a visit from the 'man from the ministry' :) 73 Cclin
Thanks Colin. You may have something with the PSU voltage. Ive not fitted a low pass filter.
fredintheshed1 one other thing to check Fred is if jt has an FM/SSB switch on the amp, try both those modes in conjunction with the modes on the radio and try it again at full power, then see if the clipping occurs in both modes. With the FM mode, the amp should run as a Class C amp with little to no transistor bias, any clipping shouldn't effect the FM modulation. In SSB mode the amp should run as a Class A or AB amp and use little transistor biasing to keep the output signal linear. Perhaps this biasing is off and appears at higher input levels, or the voltage supply is affecting this bias and killing the signal linearity, hence distortion or clipping? Just a wild thought, hope it helps some :)
Thanks Colin some very useful advice. Just what i needed and i will be running some testing in the future. Video's tend to be around 3 weeks behind so look out for it.
Hi Fred, always glad to help where and if I can :) I'm looking forward to see and hear how you get on. I did a bit of digging and found this link to the Nevada Radio site, with the specs for this Amp:
www.nevadaradio.co.uk/amateur-radio/amateur-radio-amplifiers/zetagi-b-150p
Longish thread alert... :)
This link above shows the amp input power between 0.5w and 5w to achieve the power out (60-100w for AM/120-200w for SSB).
However a few calculations of you PSU, with Power = Voltage x Current, your input power = 13.8v x 15amps = 207w. This 207w is all you have as a maximum to feed the amp.
Using the same calculation of P = V x I, therefor I = P/V, the B150 Amp needs a certain amount of current to produce the 150w using 13.8v. The current needed (using I = P/V) is 150/13.8 = 10.8amps. However this assumes the amp is 100% efficient. With Class C amps, FM mode, you get around 60% efficiency and with Class A amps (SSB mode) you get less at between 30-40% efficiency. This lack of efficiency is lost as wasted power output in the form of heat.
To get more power, then more current is needed as the 13.8v input voltage is constant. The issue here is then you may need to drive the amp a little harder with more drive power, but this in turn forces the amp to require more current. As it requires more current, possibly more than the psu can provide, the psu output drops, with this drop is a possible drop in amp biasing voltages and makes the amp work in less linear modes, hence the distortion.
Anyhoo,. sorry for the lecture, apologies if I'm teaching you to suck eggs here :)
Thanks again Colin. Interesting stats. I think i will revisit this issue in a few videos time. First job is to replace the RG58 with better RG8. Make a new patch lead and try a 30 amp supply. I will see how that goes.
I got the b-150 for a good 20 years. Has got the mrf455 as final? The amp without relay if I'm right .But if I remember it right it was for fm/am only. I have tried to use it in the past on ssb but it sounded just horrible ... must have got the original folder somewhere ,and I believe it says it there... and that was mobile , so no dc power shortage .
I had a B150 before which i used on my Grant 2 and that one worked fine. I spent all summer getting out on 20 watts with the 6900N. Iam not sure you need any more.
under your rig to the right of your speaker what is that please.
ps keep them coming
Hi ruclips.net/video/0czQFv5zdCY/видео.html
Make your box with C or N connectors. I KNOW it's hard on RG8 or H100 - but if it's over 15 metres it's worthwhile, The connectors are impedance neutral, 259s are not :)
Good thinking i had not thought of that.
It's sounds crap because there's no filtering in them. If you put a band pass filter on the output it will clean your audio up and stop the shite (harmonics) coming out of it!!!!!!
Your 9900 dont have a power killer right? You can t use the mic gain as a power killer I think..... Don 't drive I much harder than 4 watt s it won t hurt the zetagi, but your power settings on the radio should be adjustable for this.....
A99 is nothing like Gainmaster. Only thing in common is both have fibreglass radomes.
Fred what i meant to ask what is better RFC 240 uf or RG213 Thanks
Ask someone the question and you will get a different answer ever time :-) Myself i like 213 as it as tough as old boots and low loss. its reasonable priced as well.
Thank you Fred
It’s due to how many watts you push through the amp
Before it "pops"
A small a/c unit? As well as comfort, surely 100F is bad for your radio kit?
Yes its way too hot
If you change the coax you're also going to have to change the jumper cable to
Yes i will upgrade that at the same time.
FRED,, DID YOU YOUR COMMENTS TURN OFF....ANYWAY,THANKS FOR THE POST, YES FIRST ONE IN,,,,DES CREAN 68CT022
Hi Des no i re uploaded this one.
Interesting freedom of information response from OC regarding the use of linear amps. Basically, they don’t care:
www.whatdotheyknow.com/request/illegal_use_of_linear_amplifiers
I think its just they no longer have the resource available. The lines "Accordingly it is not considered to be a proportionate use of resources or otherwise in the public interest to investigate your complaint." sums it up. It will be the same with people using HF radios on 11 m.
Fred in the Shed indeed. My local planing dept. now says bluntly on their website and downloadable guide: unless a suspected breach is causing you direct harm, don’t contact us, as we don’t have the resources available to chase up minor issues.
Good days for antennas.....
The amp sounds crap because it's not getting enough current from that feeble psu .
I suffer from the same problem when my leisure battery bank starts to go flat when I'm portable .
Could be ? The amp draws 10 amps and the psu is 15 amp in theory it should be ok.
that amp will only draw 8 - 10 Amps! that power supply should be fine,
Is it legal to use a 450d for cb only?
Hi. No its illegal to use the 450 or any HF radio on CB 11 meters.
@@CB-RADIO-UK Thanks. I mean can a non amateur buy one and modify it for cb use, without issues?
Ahh get rid of the old dish Fred 😆
LOL i know i keep meaning too.
20w QRP?
3 watts into the amp.
CQ CQ CQ AUDIO TEST.
SOUNDS TO ME LIKE YOUR OVER DRIVING THE AMP
Could have been. However some people said i could have been under driving it ?
Just bought one of these the click is annoying
Just the relay kicking in.
YOU DON T NEED THE RF AMLIFIER!!!!!!! YOU NEED KNOWLEGE FOR OLD IT IS ABOUT TRANSMITTING AND HEARING GOOD AND TAKE IT MASURES FOR COAX FOR FREGUENCY TO YOU WAND IT!!!!!!
Woah LOL. No need to SHOUT. Your not making an awful lot of sense to be honest but i think i catch your drift and, well i guess thanks for taking the time to comment on the video. 73
The truth it is i HATE THE RF AMPLIFIERS BECASE I WAND IT I AM LEGAL TOO MUCH!
In the real world, QRP is max. 4 Watt...
Not on SSB = 12 watts.
No offence m8 I don't know why your arsing around with cb's that need a set of boots. you would be better off with another mobile hf radio
No offence and your quite right. I am just doing it to see whats possible or in this case not. The 9900 really does not need any more power.
Anytime I have messed around with mobile linear amps in the past they've nearly always caused complications. The only exceptions have been home based ones with a plate and load on them. Added to the things that can go wrong, you have also got all of the connections and wiring all over the shop :D My next radio will be a HF set. I'm completely disillusioned by the quality of these Chinese export style radios and for the price you can almost pick up a second hand HF radio. There's no comparison to these ssb chicken boxes :P
That would actually make an interesting video you could make m8. Comparing the reception side by side of your Alinco, Yaesu 450D, SS9900, SS6900 and your hf receiver. I find my SS6900 receives very poorly indeed.
The receive on the SS9900 is pretty good to be fair. I would say on 11 meters it can match what i get on HF gear. The transmit is a whole different story. I am going to do a video with CT2865 and he will run a 6900, 9900 and then a Yaesu 991a. The 991a audio is in another world.
To be fair the receive on the 6900 is fine as long as i dont get signals lower than 3-4 and then everyone goes very very quiet. Other than that it's just very noisy even on AM and SSB. The front end overloads on SSB if I'm talking to very local people, but that's not a problem cause dx by it's definition is not local. :D With some work ( mods to the basic radio ) it would be a fine radio indeed. It's just not worth spending the money on it.
IM WATCHING YOU WITH MENU DRIVEN CONTROLS. THE NEXT RADIO YOU BUY SHOULD HAVE KNOBS. TOO MUCH BUTTON PUSHING.
Funny you mention that. See here. ruclips.net/video/9D6FPor1avE/видео.html
your antron 99 is junk not ment to push any more than 10 watts
Das ist verboten !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Nun, das habe ich nie gewusst
You may want to try some RG 213 coax or some lmr400
You may want to try some RG 213 coax or some lmr400
I ve got 213 going to the A99 but i wont get that through the air brick. Iam going to try Mini 8. Thanks for the comment.