Yaesu FT290R RF Power Output Problem.

[M6RLT RICK]

hi , i have a yaesu ft 290r radio and it has a power output problem , if you tap the shell the power output alters from 1w to around 5w ,and then keeps altering during modulation any ideas please would be helpful other to this the radio works fine

[Brian R Pateman]

Hi Rick and welcome to the forum.

I've moved this to a more appropriate section.

You might try http://groups.yahoo.com/group/FoxTango/ which is the best source I know for Yaesu related help and information. You'll need to register but it's well worth it.


Regards,

[M6RLT RICK]

Originally Posted by Brian R Pateman

Hi Rick and welcome to the forum.

I've moved this to a more appropriate section.

You might try http://groups.yahoo.com/group/FoxTango/ which is the best source I know for Yaesu related help and information. You'll need to register but it's well worth it.


Regards,

many thanks for link my friend , unfortunatly i dont want to join yahoo at the moment , but thanks anyway , 73s

[Sean Williams]

I would suggest buying a copy of Practical Wireless, and looking for Harry Leemings column - he repaired radios like this for years, and is happy to offer advice on how to fix faults on older radios such as the FT290.

Just re read your post - The 290 is only rated for 2.5w of output power from memory. what mode are you checking power output in? FM, or SSB?

If it is SSB, then the power will change as modulation is applied.

Are we into the M6 series of callsigns now? or was that a typo?



73
Sean
M1ECY

[M0AFJ, Tim]

No they have run out of M3's, it sounds to me that the rig might be on SSB perhaps?

[Phil G4SPZ]

Rick,

Is your FT290R a Mk 1 (removable case bottom, internal C-cell batteries) or a Mk 2 (detachable battery pack on rear)? Does the fault occur when running on batteries, or on a 13.8 volt power supply? If on batteries, check all the springy connections and make sure they are scrupulously clean.

I had a similar intermittent fault on my 290 Mk 1 which I eventually traced to dirty contacts on the transmit/receive relay. With care, the top can be removed and the relay contacts cleaned with a little Servisol. It has worked perfectly ever since.

You should also check the high/low power switch which may have dirty contacts.

73

[M6RLT RICK]

Originally Posted by G4SPZ

Rick,

Is your FT290R a Mk 1 (removable case bottom, internal C-cell batteries) or a Mk 2 (detachable battery pack on rear)? Does the fault occur when running on batteries, or on a 13.8 volt power supply? If on batteries, check all the springy connections and make sure they are scrupulously clean.

I had a similar intermittent fault on my 290 Mk 1 which I eventually traced to dirty contacts on the transmit/receive relay. With care, the top can be removed and the relay contacts cleaned with a little Servisol. It has worked perfectly ever since.

You should also check the high/low power switch which may have dirty contacts.

73

hi my friend , well it is the mk1 and it does it on fm , i have a station about 1 mile from me and he cant hear me as the power drops down to almost nothing , if i tap the casing the needle shoots back up to max wattage , apart from this prob the radio is in excellent condition and would hear a pin drop in a haystack , hi hi , i will give relay contacts a clean to see if this does the job , as of yet i havent tried it with batteries so i may do this tonight at club . many thanks all for replies , M6RLT rick 73s all

[Station X]

I see from the Wanted section that you're now looking for a linear amplifier for this rig.

You'd do far better to fix your 290R than add a linear amplifier to it. If the output from the 290R, and therefore the input to the linear, goes up and down, then so will the output from the linear.

It sounds like your 290R has quite a simple fault such as a dry joint, dirty relay contacts or possibly a loose connection on the aerial socket. Best to try and fix that first. Is there not some one at a local amateur radio club who can help you?

[Antlong]

Hello Rick,

I don't use my 290 really, an occasional idle monitor of an empty calling channel perhaps - and yes, I know I could call CQ but life's too busy! The point I'm getting round to is that I read somewhere (PW?) that running without having the aerial rod in place, even if retracted, was known possibly to damage the 290's PA. Between that and the 25kHz channel spacing it may be time to look for another perhaps...

Regards Ant G0AJA

[HamishBoxer]

Could i suggest a search on the internet for known 290 faults,that may help you 73s David GM8JET

[Station X]

The point I'm getting round to is that I read somewhere (PW?) that running without having the aerial rod in place, even if retracted, was known possibly to damage the 290's PA. Between that and the 25kHz channel spacing it may be time to look for another perhaps...

If any transmitter having a transistorised output stage is operated without an aerial the transistors in the RF output stage are likely to be destroyed. This would lead to permanent low output. In this case the output varies, which could point to a very simple fault. Some rigs have protection circuitry which reduces power if there is an aerial fault. This could be the problem here.

There is nothing to be lost by trying to repair this rig before buying a new one.

Rick. What is your objection to joining a yahoo group? You could get a lot of help there.

You could try connecting the rig to a dummy load and gently poking components with a plastic knitting needle to try and locate any dry joints. A blanket resoldering round the output stage might help.

Did you clean the relay contacts as suggested? Is the output constantly high with the rig in CW mode with the key down.

[Antlong]

Hello all,

From
http://www.w1ngl.us/radios/ft290r/ft290.htm
with thanks, we have:

"NO RF O/P : PA
If it is not PA (the most likely cause) then check diode D24 in aerial switching, check for L2012 physically shorting to copper screen, and check driver Q2021 and R69."


My point about the aerial rod was perhaps badly phrased - obviously one wouldn't transmit into an open circuit anyway, but this set apparently needs the aerial rod in place even if it's fully retracted and not in use, as it would be with an external aerial.

Regards Ant

[dsergeant]

Although this would indeed seem like a dry joint or similar simple fault, before we get too far I would remind you that Rick (M6RLT) is the holder of a Foundation class licence. Therefore he can only use ready built transceivers or kit built ones and should not really be going inside rigs and doing repairs. As one involved in Foundation training myself, I have just discussed this with our other tutors who agree this is the case.

I hope Rick gets the problem sorted out, but it might be worthwhile getting somebody from his local club or one of his course tutors to have a look at it for him.

Dave G3YMC

[M6RLT RICK]

Originally Posted by dsergeant

Although this would indeed seem like a dry joint or similar simple fault, before we get too far I would remind you that Rick (M6RLT) is the holder of a Foundation class licence. Therefore he can only use ready built transceivers or kit built ones and should not really be going inside rigs and doing repairs. As one involved in Foundation training myself, I have just discussed this with our other tutors who agree this is the case.

I hope Rick gets the problem sorted out, but it might be worthwhile getting somebody from his local club or one of his course tutors to have a look at it for him.

Dave G3YMC

many thanks my friend , i am as you point out only a foundation user although i am sitting my 2e0 course at present , iwould prefer to rectify the prob myself for self gratification but sadly i have no idea how to hi hi , so i will have to pay someone to do it for me , unfortunatly the chaps in my club are all into new equipment and wont waste time on old radios , (poss looking for new club ) 73s all and thanks for advice,,,,,,,,, m6rlt rick

[Antlong]

Hello Dave,

I've not followed closely the ins and outs of the current licensing system so I bow to your greater knowledge. But whatever happened to "self-training"? Gone down the road of general political correctness perhaps!

Regards Ant

[Paul Stenning]

This seems to be wandering away from the original subject towards discussions that are not welcome here, and has already been the subject of two post reports. It is now closed.

[M6RLT RICK]

to all that gave advice i thank you , i have sorted the problem , it was a dirty joint , so again many thnkx ,m6rlt rick