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eHam Forums => Amplifiers => Topic started by: KM5PS on March 14, 2012, 01:42:10 PM



Title: icom 736 and al811h hookup
Post by: KM5PS on March 14, 2012, 01:42:10 PM
I have recently bought a icom 736 for a backup rig and I am trying to hook it up to an AL811h amp.  I have hooked up the send line from rig to amp but when I key the rig in FM mode or CW mode my plate voltage meter reads abt 140 mA and the Grid meter does not move.  I have also tried hooking up the ALC line also and get the same reading.  I never have used the amp with an Icom rig before.  I works fine with my K3 using the send line only. The icom manual says to use both send and ALC connections.  I thought before I do that and mess with the ALC adj. on amp I would ask here first.  i have the icom set at about 40 watts of drive.   

TIA
John


Title: RE: icom 736 and al811h hookup
Post by: WB2WIK on March 14, 2012, 02:56:18 PM
Sounds like it's keying just fine but not getting any drive.

Do you have a wattmeter in line after the amp?

If so, switch the amp to STBY or turn it OFF, key the rig again, see what the meter reads.  I have a feeling it might be "nothing." ;)


Title: RE: icom 736 and al811h hookup
Post by: N4JTE on March 14, 2012, 03:59:33 PM
Same advice from here, is the 736 showing anything out bypassing the amp? I use a 751a icom with a modified 811h and never use the alc connection.
Bob


Title: RE: icom 736 and al811h hookup
Post by: KM5PS on March 14, 2012, 04:38:36 PM
I have the amp off and key the 736 and shows pwr coming out abt 50 watts.  Radio read 50w and so does the watt meter that I have inline with the amp. 

John


Title: RE: icom 736 and al811h hookup
Post by: K4RVN on March 14, 2012, 06:39:23 PM
Have you tried plugging in a straight CW key to key the Ameritron amp with the 736 in the CW position using the send outlet on the 736?  The ALC is not required for this driving at 50 watts. I know these seem dumb questions but I would like to hear how you were keying the amp in the cw mode with your transceiver. Do you have a dummy load to check your 736 for 100 watts out? I use an ARB 704 on my little Icom 7200, but your relay is good for 16 volts and 2 amps listed in the manual.

Frank


Title: RE: icom 736 and al811h hookup
Post by: KM5PS on March 14, 2012, 06:55:07 PM
Frank
I have now put a straight key in 736 and get the same results as before.  I was using FM mode before to get solid carrier for tuning.  When I key the 736 with straight key (cw mode)or FM Mode the  amp still shows abt 140mA in plate meter and barely moves on Grid meter.  It does this with straight key or when I use FM mode.  My watt meter shows that I am putting out 50 watts.  Yes I do have a dummy load and the 736 does put out 100 watts. 

John


Title: RE: icom 736 and al811h hookup
Post by: K4RVN on March 14, 2012, 07:20:54 PM
I would suggest unplugging the send key cable from the amp and check it with an ohm meter for gound when keyed
with the transceiver going into your dummy load. Sure sounds like a relay problem on the send circuit since your other transceiver works OK with the amp. I don't know if like some other makes whether you have a menu item to turn on or not for a non Icom amp. I doubt it.

Frank


Title: RE: icom 736 and al811h hookup
Post by: W1QJ on March 14, 2012, 08:36:11 PM
UM, do you have the coax cables connected the right way?  Coax from the radio to amp RF INPUT and antenna to RF OUTPUT?  Leave out ALC line for testing.  The radio is keying the amp just fine because your readings are correct for just being keyed with no drive.  CHECK THOSE COAX CONNECTIONS AGAIN.  OH. Make sure both radio and amp are on the same band.


Title: RE: icom 736 and al811h hookup
Post by: WB2WIK on March 15, 2012, 08:38:35 AM
I would suggest unplugging the send key cable from the amp and check it with an ohm meter for gound when keyed
with the transceiver going into your dummy load. Sure sounds like a relay problem on the send circuit since your other transceiver works OK with the amp. I don't know if like some other makes whether you have a menu item to turn on or not for a non Icom amp. I doubt it.

Frank

It can't be that.  He's getting 140mA Ip.  If the amp was not keying, his Ip would be zero and stay that way.


Title: RE: icom 736 and al811h hookup
Post by: K4RVN on March 15, 2012, 01:38:26 PM
Yep you are right, Lou already told us that. He did say he was getting 50 watts on the watt meter in line with the amp,
not nothing like you suspected so that threw me in addition to being a little dumb here. I really don't know what the poster meant " in line with the amp." Could be backwards like Lou mentioned for him to check his coax connections. I've done that at least once myself.
 I will be anxious to see what the problem is.

Frank


Title: RE: icom 736 and al811h hookup
Post by: KM5PS on March 16, 2012, 07:18:16 PM
Well the problem is solved.  I hate to say that stupidity on my part is to blame.  The way I had my K3 hooked up and the Icom 736 were different.  I thought everything went threw my coax switches but the k3 was the only rig that was hooked directly to the amp. I took a day off of trying to figure it out and just happen to think that maybe the K3 was the only thing that was hooked up right, and sure enough it was.  Now that I have changed my cables on my coax switches, both rigs now go directly to the amp.  I guess that is a problem with two rigs, TWO many cables.  Thanks for help, I feel pretty stupid for not checking that first.  Thanks again guys for the information.   Hopefully this post might help someone else out before they do what I did. 

73's
John


Title: RE: icom 736 and al811h hookup
Post by: W1QJ on March 17, 2012, 02:39:20 AM
Maybe my CHECK THOSE COAX CONNECTIONS AGAIN   helped?


Title: RE: icom 736 and al811h hookup
Post by: K4RVN on March 17, 2012, 02:48:09 PM
Lou,
You done good, to coin a phrase, as well as some others but you pretty well nailed it. I did no good whatever.

Frank


Title: RE: icom 736 and al811h hookup
Post by: AD6KA on March 17, 2012, 03:43:45 PM
Quote
Well the problem is solved.

Glad to hear it, and super glad it wasn't something
serious or expensive!

Quote
I feel pretty stupid for not checking that first.
Don't beat yourself up. We all have made (or make) those kinds
of mistakes during some point in our careers.

What you might do is label your cables if you have
more than one rig, or antenna, so this won't happen again. One way
is to hand laminate (only needs pressure) a small tag between
two layers of clear Dupont "Mylar D" tape.
(The "D" is important)
You can find this at a good art store or library supply store
It is pressure sensitive (sticky) tape with an aggressive
acrylic adhesive,  so it is easily used to hand laminate labels.
Two Mil thick tape works FB.

Tape a label tag to both ends of rig coax cables
and the indoor end of every antenna and rotor control cable.
And it's not a bad idea to also label stuff like amp PTT
cables, RTTY Keying cables,  Audio Out and Audio In cables
that go to the rig's rear panels, etc. Don'tcha just hate having a loose
cable with a connector and having to pull the radio forward
or sideways and figure out what it is?

It's not much work and you'll be glad you did it,
especially when some piece of gear craps out in the
middle of a contest and you are tired, sleep deprived,
PO'd, and hurrying to patch in a replacement.
THAT'S when Mr. Murphy likes to show himself!  ;D

73, Ken  AD6KA


Title: RE: icom 736 and al811h hookup
Post by: W1QJ on March 18, 2012, 10:53:14 AM
Lou,
You done good, to coin a phrase, as well as some others but you pretty well nailed it. I did no good whatever.

Frank

Who said that Frank?  I'll split it with ya :D


Title: RE: icom 736 and al811h hookup
Post by: K4RVN on March 18, 2012, 09:32:12 PM
Actually two of my favorites, Larry the cable guy and Jeff Foxworthy so you don't need to split. BTW Larry was born in Nebraska. Jeff's dad was an IBM exec, so they are both an act, not real rednecks like me.

Frank


Title: RE: icom 736 and al811h hookup
Post by: W1QJ on March 19, 2012, 05:14:35 AM
Frank, really, I don't mind sharing with you.  I don't know what Jeff has to do with it, but I watch his show all the time, I love it.  I am also a Jeopardy freak as well.  My wife says I should go on the show.  But, to stay on topic.  A few years back when the economy was doing real well a ham friend of mine who was the Dean of "outsource education" in a local technical college offered me a part time job.  It was his job with the college to provide teachers for outsourced education.  Big companies would contact the school and ask to provide courses for their employees on site.  They would get all sorts of requests, like teaching lanugages etc.  He got a request from a company to send someone in to give a course on "electronic/electric troubleshooting" .  His job was to gather the information on exactly what they wanted then find someone to teach a course about what they want.  When he got this particular request he thought of me because I had done repairs on his amplifier, and his old Swan 350 and I rewired his whole basement when he finished it off.  He figured that I had both bases covered, electronic and electrical.  So I took the job and worked up a course to teach the workers at this company on how to go about troubleshooting problems with equipment.  The basis of the course was to establish a plan of attack when something was not working.  I gave them a flow chart.  Following the flow chart would lead them to a fix or a decision that more advanced repair was needed and the equipment would need to be pulled and sent out.  We went into ohms law and power law as well as learning about fuses etc. I always got a laugh when I told them to make sure the unit was plugged in and hooked up correctly.  Many of us think too big when something does not work.  We overlook the small stuff.






Title: RE: icom 736 and al811h hookup
Post by: K4RVN on March 19, 2012, 06:07:29 AM
Interesting Lou and true in my experience. As I mentioned in a previous post I have conected my cables wrong at least once that I can recall, (other times I forgot). It is the simple things some of us overlook as you say " thinking too big". I also have the fault of engaging my keyboard before my brain. I am glad the problem was discovered and he should not feel like the lone ranger as in my long years as an amateur I have made many mistakes and look foward to some more before I quit.
Jeff lived about 20 miles from me in Hapeville, GA. and his dad worked in Atlanta for IBM. I did not personally know either.

Frank