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Author Topic: Strange Ft-101EE Mods  (Read 10914 times)
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K4PDM
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« on: April 28, 2009, 11:34:50 AM »

Hi, I'm new to the group and haven't operated AM in many years, but I recently purchased an FT-101EE and am seeing posts as to how it is a pretty good AM rig.
The seller told me that the radio had the AM filter, but in actuality in the slot for the SSB filter is a filter with a typewritten sticker saying "AM Filter 4 KC" and giving a stock number. There is no filter in the other slot.

It sounds much narrower than a 4kHz filter when I listen to an AM signal, but my AM audio sounds very, very good when I listen to myself on a portable SW receiver.

My theory is that someone labelled the SSB filter as an AM filter, but rigged it so that AM transmit goes thu the top filter slot--where there is no filter--so it transmits a very wide signal.

Has anyone seen a real AM filter in a 101 labelled this way and used in the SSB filter slot? Or, has anyone seen a 101 modified so that AM transmit run thru the top slot with no filter in place?

Tnx 73, Paul K4PDM


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N3DRB The Derb
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« Reply #1 on: April 28, 2009, 12:11:07 PM »

The AM filter goes in the cw filter position ( on top)  and you have to make some small changes in the rig to get it working.  Most likely is the guy simply lied about it having an am filter at all and the original ssb filter is still sitting there. It's possible it's been hacked in some manner, FT101's were hacked a lot by cb er's.

FT 101's r good radios for AM, suitably enhanced with some mods to some of the boards they sound as good as anything out there.
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KA2QFX
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Mark


« Reply #2 on: April 28, 2009, 12:17:49 PM »

If it sounds narrow it's probably a SSB filter. When you tune through the marker signal you should get full response over at least 6KC before the signal drops off. If you don't, it's probably a SSB filter.

Also, the filters only function on receive. The modulation occurs on the low level 3.180 MHz IF stage and then gets mixed directly into the transmit chain.  

The top filter slot, normally wired for CW filter, requires a modification to the mode switch to switch it in for the AM filter. An unmodified mode switch would otherwise use the SSB filter for AM. Mods are posted here and several other places on the web.  If their are two capacitors on the back of the IF board, connecting between the two filters, if so it's set up stock.  If the filter(s) were bypassed in AM it would be VERY, VERY wide oin receive.

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K4PDM
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« Reply #3 on: April 28, 2009, 12:24:09 PM »

It does sound like the SSB filter on receive, but it sounds wide on transmit when I listen to myself on a portable SW receiver.

The radio will modulate when in the "tune" position, so I took that as a sign that the AM filter mod was done...but as I said, there is no filter in the top slot, just a filter in the bottom slot that has a typewritten sticker saying "AM Filter 4 KC."
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ke7trp
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« Reply #4 on: April 28, 2009, 12:49:30 PM »

The others have laid this out for you.   You need to verify that the Mode switch was modified correctly You can test the Reciever while broadcasting with another rig and receiving on the 101. Zero beat the incomming Carrier. Then roll the VFO left to right. Should have 3 KC either side. If not, The filter is not wide enough. You can buy Filter boards on Ebay and you can also post on Foxtango.org. Its a great site for this radio.

On AM, Make sure you keep the carrier down to 20 watts or so.  About .15 on the IC meter. 101s can sound as good as any Ham Transmitter out there. The hands down best all around mic for the 101 is the Sure 444.  It has great wide clear audio. I love my 101s. I own two complete sets and two sets of 101 twins. I dont use them much anymore though.

If you have any other questions, let me know. I have been using these radios for 10 years or more.

Clark
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KA2QFX
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Mark


« Reply #5 on: April 28, 2009, 12:51:43 PM »

Modulation in TUNE position is a 99% indicator the AM filter mod was done on MODE switch.  
As I said, the filters are NOT part of the AM transmit path on this radio, with or without any modification.  
Good luck with the radio, I run one on AM as well.
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Pete, WA2CWA
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« Reply #6 on: April 28, 2009, 01:07:24 PM »

You can always do what Drake did with the TR-6. No AM filter; just connect a 10K resistor from filter input to filter output.
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K4PDM
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« Reply #7 on: April 28, 2009, 01:13:50 PM »

Sorry, I missed the part of the reply about filters not being in the transmit path.

If the mod were done, AM mode would use the top filter slot for receive. But there is no filter there! I can receive in AM mode, but it sounds real narrow and not very good. Maybe only part of the mod was done.

Did anyone ever make a 4kHz filter for the 101? Or is the typewritten sticker on my filter a fake to fool the gullible (it fooled the guy who sold it to me, I trust him.) I realize even if it is a 4Khz filter, that's an odd value and not really wide enough.

I don't know how much I will use the FT-101 on AM, but the transmit does sound pretty darn good on my portable SW receiver.

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ke7trp
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« Reply #8 on: April 28, 2009, 03:15:50 PM »

I have never seen a 4KC AM filter for these.. I have seen 5 and 6 KC.  Try the 10K resistor trick.. SOunds like it would work.. Smiley

There are lots of AM activity these days!   40 meters 7293 at 11:30AM,  3870,80,85 in the evening and night and also 1885 in the evening. You might find you run more AM!

If you discover alignment issues let me know. I have aligned probably 100 of them in my time.

Clark
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N3DRB The Derb
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« Reply #9 on: April 28, 2009, 03:22:31 PM »

Quote
can receive in AM mode, but it sounds real narrow and not very good.


it's got the ssb filter in there. yeah, whomever sold him the rig screwed him over, or maybe he didnt know. But you got hit too, unfortunately.  Tongue


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K4PDM
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« Reply #10 on: April 29, 2009, 10:18:17 AM »

I didn't really buy it for the AM filter, it was just a little bonus.

Too bad its not really there.

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flintstone mop
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« Reply #11 on: April 30, 2009, 11:52:59 AM »

OK Paul,
It seems like you're pretty close to making a contact with your FT101-EE
I had an EE, which was the "economy" model and the TX audio was superb!
Are you going to drive a linear or run barefoot 20W?
Get some on-air ears to get your radio up and running. Hook 'er up to an aerial and play radio.

Fred
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Fred KC4MOP
K4PDM
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« Reply #12 on: April 30, 2009, 12:08:16 PM »

I don't have an amp right now so it'll be 20 watts. I listened to two guys last night on 3885 and almost tried to join in, but I didn't.

I have made some SSB and CW contacts and it does work fine in those modes, so I'm happy with the radio.
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KX5JT
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« Reply #13 on: April 30, 2009, 01:05:39 PM »

I don't have an amp right now so it'll be 20 watts. I listened to two guys last night on 3885 and almost tried to join in, but I didn't.

I have made some SSB and CW contacts and it does work fine in those modes, so I'm happy with the radio.

Trying to work AM on 3885 with 20 watts at this time of the year will likely be an excersize in frustration.  The noise levels are up and most of the 75/80 meter AM stations are running 100 watts to legal limit plus.  40 meter is much more doable with that power level.  Last night I had a nice qso after midnight with a fella in Colorado and he was S9 at times with 30 watts.  But nonetheless, fire it up and give it a shot whereever you may!
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AMI#1684
K4PDM
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« Reply #14 on: April 30, 2009, 01:14:06 PM »

That sounds great, John. I get up at 3:30AM eastern so I don't stay up very late, but I do turn the radio on when I get up. This morning 40 was nothing but static, but I'll get in there soon!
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W3GMS
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« Reply #15 on: May 01, 2009, 09:49:41 AM »

Paul,
It looks like one way or the other your going need to find a 6Khz filter.  Here is an outfit that has been in business for quite some time that sells 6Khz filters for the 101.  I have bought filters from them and they work well. 
 
http://www.qth.com/inrad/about_ir.htm

I have several 101's along with the Yaesu Twins which are the FL-101 and FR-101 along with all the station accessories.  The gear works great and when modified sound fantastic.
Enjoy,
Joe, W3GMS
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Simplicity is the Elegance of Design---W3GMS
K4PDM
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« Reply #16 on: May 13, 2009, 12:44:54 PM »

In case any one is wondering, I removed the typewritten label from my filter and discovered that it is, indeed, one of the original Yaesu filters. Someone was engaging in a little "creative marketing" when they typed the label up.

So if I am to operate AM, I will need to buy a filter. And if I want a CW filter in the optional slot, no AM for me.

At any rate, I'll not be on AM mode with the 101 for at least a while. Thanks, everyone.

73, Paul K4PDM
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ke7trp
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« Reply #17 on: May 13, 2009, 12:56:20 PM »

Since the filter is only recieve, You can just put a small switch under the cover that jumps the filter. This will get you wide AM.

Clark
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Ed KB1HVS
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« Reply #18 on: May 19, 2009, 02:51:20 AM »

You guys probably already know this but the AM mode switch needs to be modified......
http://foxtango.org/ft101/graphics/FT101-AMFILTER1.JPG
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KB1HVS. Your Hi Value Station
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