[Yaesu] FL-2100B Question

Wed May 4 22:41:24 EDT 2016

>From my experience with them usually when the bandswitch is arcing its because the bandswitch has already been roasted by someone tuning up with a lot of power applied, the contacts on the switch get pitted and then it creates a nice little spot that arc's and it will continue to do so.  I had to replace the bandswitch on a half dozen or so of them now, got three more on the shelf waiting for their repairs as well.  The bandswitch is the weakest part of these otherwise great old amps!  Cleaning it might help, but its only putting a bandaid on a broken leg, eventually it will just melt a contact off, usually on 40 or 80 is where most of the dead ones I got are damaged.  The spacing on the original Yaesu switch is just marginal for the voltages present, they all fail about the same way.  

There is a replacement available for them, first off there is a really stout and well made but quite expensive replacement from Multi Tech, I helped them design this replacement about two years ago, he makes them in really small production runs at their plant, they are very nice, well built, but super spendy!!  I have used a couple of them and I can attest to their quality, but I know not everyone has the kind of wallet to buy one.  The advantage to them though is they are quite overbuilt, better spacing, more insulation, and corona shields to help prevent any flashover.  The only other issue here is the Multi-Tech switch is slightly larger in depth and requires a few small modifications to get this beast installed, but I have done it and its not that hard.  I have another one on the bench now that’s getting a MT switch.

http://www.ebay.com/itm/Replacement-Band-Switch-For-Yaesu-FL-2100-Series-Amplifters-/231497195410?hash=item35e64edf92:m:mHzSreLHJZVAcF4DXf51CqA

Now, the cheaper option, and yes I have used a few of these as well!!  They are made in China, but I have spoken with the seller a few times when he first offered them for sale and the bugs are worked out.  For the cost of them, you could buy four of them and still be less then the better MT switch and have spares, but your probably going to need them because they are based on the exact same design as the Yaesu original, it’s a true clone of the Yaesu switch and doesn’t need any modifications, but eventually it suffers the same failure if not treated gently.

http://www.ebay.com/itm/Band-Switch-replacement-For-Repairing-FL-2100B-5-Bands-Amps-/171796838623?hash=item27ffe3b8df:g:aU4AAOSwrklVYAef

I have put a few of the Chinese clones in, they do alright, provided that you tune up carefully with very little power applied and due diligence in operation.  The MT switch on the other hand I abused over a contest weekend to see if I could actually kill it and couldn’t, whereas the clone would arc and fail just as fast as the original in the same operating conditions.  My suggestion though, is its probably time for a new bandswitch.  My amp with the MT switch never arc’s, even with an oops during tuneup.

73,

Scott KB0NLY

-----Original Message----- 
From: Gary H. Harmon, Jr. 
Sent: Wednesday, May 04, 2016 8:49 PM 
To: YAESU  
Subject: [Yaesu] FL-2100B Question 

I'm helping a nice fellow in Utah bring a FL-2100B out of hibernation.  So
far so good.  Right now there is some blue arching happening on the
bandswitch when turning the Plate variable.  I suggested he spray Dexoit5 on
the contacts and rotate the switch a number of times.  I also suggested he
examine the contacts to make sure they were clean and making full contact on
both sides of the contact assembly.  Otherwise the amp seems to be working
fine.

Am I am on track here with my suggestions and/or there other things he
should do??

Thanks.

Gary H. Harmon, Jr. - K5JWK - HAM Radio and ATARI Archaeologist

6003 Archwood

San Antonio, TX 78239-1504

210.657.1549 home

210.884.6926 cell and text

210.657.1549 fax (with prior notification)

gharmon at idworld.net

"Too many projects - Not enough time!"

"Retirement = Every day is a Saturday except Sunday"

http://www.grissomroadcoc.org

______________________________________________________________
Yaesu mailing list
Home: http://mailman.qth.net/mailman/listinfo/yaesu
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Yaesu at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus