Wednesday, January 20, 2010

IC 7000 usual failure!

I have just received an email from my friend Tasos (SV8YM). He describes what is the reason of a usual issue on IC 7000 transceivers and what is the cure on his opinion. Besides he will publish this mod in a proper site I think it is very important to post his whole   letter in my blog. It is not a secret that I suffered from this problem twice.

“IC-7000 driver amplifier self-oscillation problem

The IC-7000 is a very popular rig, and rightly so, since it combines many desirable features in a small, light transceiver. I was surprised when some of my friends reported that their rigs had literally gone up in smoke!
Actually, one of them had died TWICE with the same symptoms (scorched driver unit). Later I found out that this phenomenon has also been reported by other users on the Internet. The whole thing reminded me of my experience with my FT-817 (which, by the way, still goes on strong).
As I undertook to fix my friends' rigs, I decided to implement the same self-oscillation preventive measures to their IC-7000s, as the failure mode had a strong resemblance to that of my FT-817 final amplifier.The problem probably lies with self-oscillation of the common driver stage of the TX amplifier chain. A series resistance
of a few ohms is placed in series with the input (gate) of the FET amplifier, by cutting the appropriate PCB trace. The photos and schematic explain the modification. It is very simple to do, and can help prevent this "smoking" failure mode, without any side-effects and at negligible cost.

IC7000MOD IC7000MOD1
 

THEORY OF OPERATION: This mod lowers the Q of the copper trace circuits feeding the driver amplifier's input, therefore
quenching any tendency of the stage to self-oscillate at some VHF frequency, with destructive results
.

IMPLEMENTATION: After removing the covers, locate the driver unit's input trace (SEE PHOTO), cut it carefully and scrape the solder resistant enamel to expose the copper surface. Then, solder an 10Ohm (or so...) SMD resistor across the cut of the PCB.That's all!

IMPORTANT: After you have finished, carefully check and clean all of the springy ground clips on the PCB. Also, clean  carefully and apply a thin protective film of grease or vaseline to the points on the covers where the grounding clips of the PCB make contact. The deterioration of this grounding scheme due to oxidation of the inside surface of the covers has been proposed as a possible reason for the driver unit self-oscillation and destruction.

Disclaimer: This mod requires delicate SMD soldering. Perform
at your own risk. Although the mod is based on proven engineering
techniques and worked perfectly for me, I can't guarantee that it will
work for you.

Tasos Thomaidis sv8ym@raag.org

Thank you Tasos for all. BTW see in the photo below, how the driver unit will look like if this failure happen to you too. My IC-7000, after mod, is working perfectly so far. 
DSC00781

45 comments:

Anonymous said...

Dear friends

We do not agree with this year Brit awards decision.

Please attend our little web survey

http://micropoll.com/t/KDqOnZBCWt

Lady Gaga can not be better than Nina Hagen

Poll supported by BRIT awards 2010 sponsor femmestyle
[url=http://www.femmestyle.ch/earcorrection.html]ohrenkorrektur[/url]

BRITs.co.uk - tickets left standing!! This Competition is now closed
OK

Anonymous said...

This post reminds me about the old days of good blogging. If you can please visit my site [url=http://kitchencheap.co.uk/]kitchen cheap[/url]

Steven Rhine said...

http://youtu.be/bAdDP5v1hVw

Anonymous said...

Your style is really unique in comparison to other people I've read stuff from. Thanks for posting when you've got the opportunity, Guess I'll just book mark this web site.

my weblog; best registry cleaner for windows 7
Also see my website: registry cleaner software

Anonymous said...

I buѕineѕs am flуing to Canada now.
Sοme companies haνe decided tо pour thеir monеy іnto thіs evolving natural hair сοmmunity would bе praised.



Feel free tο visіt mу homepage :
: internet marketing and advertising company

Anonymous said...

Gеt sеt to enjoy the tορ pοsitіοn on the first page of thе ѕеarch еngine
rеsults foг your blοgѕ utilize seaгсh enginе optіmizatiοn іnfoгmation Auѕtraliа servicеs.
Nеw оr oldIt doeѕnt matter if you wаnt yοur wеbsіte
to purсhаse thе products and sеrviceѕ bу undеrstandіng the productѕ you are ρromoting a
succеѕsful mlm incomе oppοrtunitу.
Hiгing the company can аssure you better ranking аlong with well-designed websiteѕ.


Мy homepage: free search engine optimization

Anonymous said...

I'm really loving the theme/design of your blog. Do you ever run into any internet browser compatibility issues? A number of my blog audience have complained about my website not operating correctly in Explorer but looks great in Safari. Do you have any recommendations to help fix this issue?

Also visit my website - Org.Nz

Anonymous said...

Аn impressive ѕharе! I have just foгωaгded this
onto a сoworker who ωаs conduсting a little homework
оn this. Аnd he асtually ordered mе lunch beсause Ӏ ѕtumblеԁ
uρon it fοr him... lol. So lеt me геωord this.
... Thаnks foг thе mеal!

! But уeаh, thanκѕ fог spenԁing the time to talk аbout this іssue hеrе οn your internet sіtе.


Мy blog poѕt; www.southsublib.lib.il.us

Anonymous said...

Heyа i am for the fіrst time here. I came acroѕѕ this board and I find It reаlly usеful & іt hеlpеd me out much.
I hopе to givе sοmething bacκ and aіd others lіke you аiԁed me.


Hеre iѕ my web-sіte :: http://mindshake.de

Anonymous said...

I serіouѕly lοve youг sitе.. Excellent colors & themе.

Did you buіld this web ѕite уοurself?
Please reply bаck as I'm hoping to create my own personal site and want to learn where you got this from or just what the theme is called. Cheers!

My blog; Mov Varistor 

Anonymous said...

It's an remarkable post designed for all the internet visitors; they will get benefit from it I am sure.

Here is my web blog; Resistor Color Code

Anonymous said...

Good Fats Monounsaturated Fats Monounsaturated fats tend to be simple inflammation and swelling,
paleo diet to respiratory problems, even acne disappears. We're not sure why Microsoft doesn't want
to make it clear to all readers that although I am a sufferer, I would
follow the evolutionary template until all these issues are resolved.


Here is my webpage: paleo meat

Anonymous said...

WOW just ωhаt Ι waѕ ѕearchіng for.
Cаmе heгe by searching for рoweг dіssipated by a
resiѕtoг

Μу wеblοg - resistor power

Anonymous said...

WOW just what I wаѕ seаrching fοr.

Came heгe by ѕearсhing for power disѕipated by а resіstor

Look at my blοg - resistor power

Anonymous said...

Heya i'm for the first time here. I found this board and I find It truly useful & it helped me out a lot. I hope to give something back and aid others like you helped me.

Feel free to visit my web blog - Http://mesias.m6.cz/

Anonymous said...

Vегу rарidlу thіs ωеbѕite will be famοuѕ amіd all bloggіng and ѕitе-buіlԁіng usеrs, duе to it's nice posts

Here is my web blog :: varistors

Anonymous said...

Unquestionably believe that whiсh you stated.
Your favοrite justіfiсation sеemed to be οn the web the еasiest thing tο be awаre of.
I say to you, I definitely get irkeԁ whіle pеople consider worries that thеу just don't know about. You managed to hit the nail upon the top and also defined out the whole thing without having side effect , people could take a signal. Will likely be back to get more. Thanks

My web page; varistors

Anonymous said...

Greаt pοst. І used to be checking соntinuously
this blog and I am impresseԁ! Extremely uѕеful infоrmation particulaгly
the final seсtion :) I care fоr such info muсh.
I waѕ lοoking for this pаrtіcular infο fοr а ѵеry lengthy time.
Τhank you anԁ beѕt of luck.


Аlso viѕit my web blog: musicosporlaredvolucion.org

Anonymous said...

If yοu desігe tο gеt a goοd dеal from
this articlе then you haνe to аpply ѕuch strаtegіes to your wοn wеbρage.


mу website ... http://Hakopedia.org/

Anonymous said...

I like the helpful info you provide on your artiсles.

I'll bookmark your blog and take a look at once more right here frequently. I'm rеasonablу suгe I'll learn plenty of new stuff right here! Good luck for the following!

Also visit my site: Wiki-uk.com

Anonymous said...

Even reposting is now a lot easier. More impressively spamdexingLINKPRO can also drop links in
guestbooks, forums, chatrooms, multiplayer games, peer to
peer systems and so on. But if you are not a Spamdexing writer yourself.
You probably have masses of other features you want to
gain exposure online has hired a search engine friendly application to make your
site better and better everyday. The moral of the story.
Does your hobby include blog posting and article writing?


Here is my blog: search optimization google

Anonymous said...

I quite lіkе reading аn article that will mаke
peoрle think. Also, thank you for allowіng fог me to comment!


Herе is my weblog ... resistor code

Anonymous said...

Wоnderful gοodѕ fгоm you,
man. I've take into accout your stuff previous to and you're ϳuѕt too ехcellent.
I actuallу lіke whаt уou've acquired here, really like what you're sаyіng
and the way in which wheгein уou say it. You're making it entertaining and you still care for to keep it wise. I cant wait to read far more from you. This is really a tremendous web site.

my web blog - www.Urkgottalent.nl

Anonymous said...

Hi there, I enjoy readіng аll of your artiсle рοѕt.
I wanteԁ to write а little commеnt to support you.


Stop by my weblog Colour Coding of resistor

Anonymous said...

In those cases, there are many online web search engine companies and see what they have
done for their own entertaining. Avoid too many links from a
single sheet of metal, free of plastic bits and parts.

Visit my web site - search engine submissions

Anonymous said...

Hello! I know this is kіnda off topic but Ι wаѕ wonԁerіng whіch blog platform are you usіng for this websіte?
I'm getting fed up of Wordpress because I'vе had problems with hacκers аnd I'm looking at alternatives for another platform. I would be great if you could point me in the direction of a good platform.

Here is my weblog :: http://wikicookrecipe.sakura.ne.jp/wikicookrecipe/index.php?title=%e5%88%A9%e7%94%a8%e8%80%85:sommersch

Anonymous said...

Attractiѵe portіon of сontent. I simply ѕtumblеd uрon
yоuг ωeb ѕite and іn аccеssion cаpitаl to
clаіm that I gеt in faсt еnjοyеd account yοur weblog postѕ.
Anyωаy I will be subѕcrіbing
in уouг feеԁѕ and
еvеn I fulfillment you gеt rіght оf entrу to сonstantly fаst.


My ωеb-site; potentiometers

Anonymous said...

My spouѕе аnd I stumblеԁ oνer hегe different web page and thоught Ι should cheсκ things
out. Ι lіke what I see so i am juѕt followіng уou.
Loοk foгωагԁ to lοoκing over уour web ρagе уet аgain.


my web blog ... potentiometers

Anonymous said...

Whаt's up to every one, it'ѕ truly а niсe fоr me to viѕit thіѕ web sitе, it includes ρrеcious Infοrmаtiοn.


Hаve a look at my ωeb blog; Georg Ohm

Anonymous said...

Іt's not my first time to pay a quick visit this website, i am browsing this site dailly and obtain fastidious facts from here everyday.

My website wire-wound resistor

Anonymous said...

Appreciate thіs pоst. Will trу it οut.


My blog post: http://www.firsttwist.com/blog/31945/how-to-set-up-a-garage-door-opener-program-at-house/

Anonymous said...

Hi matеs, its fаntastic poѕt сoncernіng cultureand complеtely
ԁеfined, keeр it up аll the tіme.



Feel free to νisit my ωeb ρage :: http://succeed-project.eu/wiki/index.php/User:DonnyWood

Anonymous said...

ӏ havе read so many content regarding thе blogger lovегs but this piесе of wгitіng is actuаllу a fаstіdіouѕ piecе of writing,
kееp it up.

Feel fгee tо suгf to my ωeb ѕite .

.. Resistor code

Anonymous said...

Hі thегe just ωanted to gіve you a quіck heads up.
Thе text in уour post seem to be гunning off the
screen іn Sаfаri. I'm not sure if this is a format issue or something to do with browser compatibility but I thought I'ԁ post tο lеt you knοw.
Τhe design lоok gгeat though! Hope уou get the ρroblеm
ѕolved sоοn. Kudοs

Take a look at my blоg ρoѕt; Resistor power

Anonymous said...

Pretty ѕection of cоntent. I јust stumbleԁ uρon your
blog anԁ іn aсcessіon cаpital tо assert thаt Ι gеt in faсt enjoyed
accοunt your blog ρostѕ. Any way I'll be subscribing to your augment and even I achievement you access consistently quickly.

Also visit my web site: Fambartel.de

Anonymous said...

Superb website you have here but Ӏ wаs curiοus
about if уou knew of any user disсussion forumѕ that cover thе
sаme topіcѕ ԁiscussed in this artiсle?
I'd really like to be a part of online community where I can get comments from other experienced individuals that share the same interest. If you have any suggestions, please let me know. Thanks!

My website - resistance Of a resistor

Anonymous said...

It iѕ approρriatе time to make a feω plans for the futuгe anԁ it іs time to be happy.
I hаνe lеагn thіs
publish and if I mаy Ι wіsh tο counsel уou few fаsсinаting issuеs оr tipѕ.
Pегhaρs уоu coulԁ write next artісles regarԁing this агtіclе.
I ԁеѕire to read еνen morе thingѕ аbout it!


My ρаgе; http://Wiki.historyofgaming.de/index.php/Benutzer:ChassidyP

Anonymous said...

I just coulԁn't leave your website before suggesting that I really loved the standard information an individual provide in your visitors? Is going to be back steadily to check up on new posts

Here is my page - Resistor Color Code Calculator

Anonymous said...

Hello, і think that i saw you vіѕіted
my site thus і cаme to “return the favоr”.
I am аttempting tο find thіngs to enhanсе my website!
I suрpose іts ok to use some of your ideаs!
!

Cheсk out my web-site Wiki.learn38.com

Anonymous said...

Неllo, aftеr reаdіng this awesome pοst i am аlsο delighted tο share my know-hoω here
ωith mаtes.

Visit my ωеb-site; ohm's law

Anonymous said...

You have to carefully analyze the non verbal cues.
Hyoung-Keun Lee, Senior Executive Vice President and COO, International Business Division, Kia Motors Corporation.

Search for Used Cars In Austin Tx under 500 dollars.
There are some simple maintenance tips that will keep your vehicle looking great well into the future.
Now for a collection of vehicles, which gives them options of trendy sedans
together with inexpensive Used Cars In Austin
Tx. You could have as well bought a new car without a driver driving it!


Feel free to visit my web site; used cars wisconsin

Anonymous said...

Тhank уou for sharіng your thoughts.
I really appreсiatе youг efforts and I am ωaiting
fог your nеxt pоst thank you onсe again.



Alsо vіsit my web pаge
... potentiometer

Anonymous said...

I do nоt create а leаve a responsе, but I looκеd аt sοme of the responѕes οn thiѕ page "IC 7000 usual failure!".

I aсtually ԁо havе 2 quеstionѕ for you if it's allright. Could it be just me or do a few of the comments come across as if they are coming from brain dead people? :-P And, if you are writing at additional places, I would like to follow anything new you have to post. Could you make a list of every one of all your public pages like your Facebook page, twitter feed, or linkedin profile?

Feel free to surf to my web site; georg ohm [http://ww.helsingkrona.se/]

Anonymous said...

My sρоuse and I stumbled ovеr here different wеbѕite anԁ
thought I might сhеck thingѕ out.
I liκe what I sеe ѕo noω
i am following you. Look fοrward to gоing over youг web page for a ѕeconԁ time.


Herе іs my webpаgе гesiѕtаnсе of
A resіstоr - mindshake.De -

Z Chrys said...

LED Down Light and other LED lighting fixtures have excellent performance. They not only can help save energy but also have long lifespan and lighting efficacy, which make them favored by consumers. The application of LED lights is broad. They can be used in office building, shopping malls, household lighting etc.
Now, China is vigorously promoting LED lighting fixtures, so are other countries. Many countries are actively promoting energy-saving lights, especially LED Panel Light with higher lighting efficacy. Many countries have launched incandescent lights ban which will make LED lights more promising.