New to me MARKIII and 180 amp *Help*

[sixonethree]

Hey guys,

First I'd like to say hello from NW Indiana.
I've been playing with radios for the past couple of years, all of them solid state. I came across a Browning Mark III along with a 180 Business Telephone Amp and sent them to Greg Barkett to have everything gone through. He changed some of the tubes, caps and resistors and I just got it back last night. I only have the directions for the radio, not the amp. With the amp off, I'm seeing a dead key of 3 watts and it's swinging up to 6 watts. I don't have a dummy load and am using an Imax 2000 with a very low standing wave ratio. Should I be seeing more swing out of this radio? I understand that there is a slot for a screw driver on the transmitter which will allow me to tune it to the antenna. I'm going to try that when I get home to see if I can get any more "swing" out of the radio.
As far as the amp goes, I really have no clue how to set it. When I turn it on, and key, it's dead keying 25 watts and swinging up to 50. What kind of numbers should I be seeing with that amp. Can anyone shed some light on how to properly operate the amp?

Thanks in advance,

SixOneThree

[crazybob]

Hi, SixOneThree. Your wattage #'s sound in the right ballpark, although on the lower side. My 180 amp. does 40-90 watts or more, depending on the watt meter being used.

I key it up for about 5 seconds & turn the tune & load knobs for the most peak swing while yelling "AUDIO". The yellow indicator light should get brighter. ..3's, crazybob.

[sixonethree]

thanks for the reply CrazyBob! So it's not unusual to have your swing double the deadkey with these radios? I was expecting a little more swing and have been told that I can get close to 150w out of the 180amp. Are these numbers unrealistic? I'm using a DOSY test station which jibes number wise with my Palstar 2000. I know it's not a bird but it's all I got. Should I even bother trying to tune the transmitter bias with my antenna or does the 3watt dead key, 6 watt swing sound ok?

Thanks again!

SixOneThree

[gator7]

Keep in mind that you want the needle to be in the center of the bias box when you dead key. As for the 3 watts swing to 6. That is about right. My MK III keys 3 and swings to 7-8 watts. So if you do play w/ the plate tune. Remember to keep an eye on the bias.
Welcome to the forum.

73's

[sixonethree]

thanks for the reply gator. The needle is a more to the right of the bias box so I guess the first thing I should do is adjust that. This is how it came back from Bartletts but I know that things can change in shipping and then the fact that the tubes and caps are new. The numbers I'm talking about were on my Dosy reading PEP. Thanks for the advice and I can't wait to get home and tinker!

SixOneThree

[FIXR]

The bias is checked with the mode switch in one of the sidebands and the meter switch in the MA position. The average AM output is 3-4 W of dead key and 10 W of audio.
The 180 output driven by a MKIII is about 100W of audio.

Alan

[Tombstone (R.I.P.)]

Adjust the plate/tune on the transmitter for max output first. Then adjust the separate bias adjustment on the back of the transmitter and you want it to read in the middle of the little section on the meter that was stated earlier. I assume that you're running an unamplified mic such as a bananna mic or D-104 G stand which will give you the best results rather than a power mic as far as modulation goes. There's a modulation adjustment on the transmitter deck which should be close to wide open. On the 180, turn the tune and load controls for max modulated power and then keep turning the load control clockwise until you lower the output by a few watts, this keeps the amp from runnung too hard an will give you more forward swing. My Mark III is dead keying about 4 I/2 watts and swinging to about ten to twelve with a G stand mic, but if all you can get out of the radio is three watts dead key thats ok too. Rather under drive for clarity than over drive somthing and sound like crap.

Tombstone

[sixonethree]

thanks for the advice everyone, I appreciate it greatly. I'm feeling a little less lost on the radio and AMP now. I read the instructions for the radio and seem to have everything dialed in. I'm not sure if my meter is a little "tight" or if my radio is just week but I'm only getting about a three watt deadkey. Doesn't seem to make a difference though as I'm getting great audio reports.
I was also able to tune the amp to the best of my newbie ability and was deadkeying 50watts, swinging 130 pep. I was rocking and rolling for a while but my volume control on the first 1/4 was messed up. I figured I'd try to blast a little contact cleaner in it. Evidently, I fried the potentiometer because it quit turning on. It was acting goofy before I did my "cleaning" so I figure it was on it's way out anyhow. Unfortunately, maycom is closed tomorrow otherwise I'd drive up there to replace it.
Arrrggggggg I've been dreaming and day dreaming about this radio and now that I have it, something breaks, lol. Luck of the draw and story of my life! :0 I know how it is, restore something, fix something up and the weakest link WILL pop. Anyhew, thanks for the advice and I look forward to being an active forum member.

SixOneThree, NW Indiana

[gator7]

Alan from tubes plus can help with the switch/volume control. I had to get one from a few months back.

Good luck with the browning.


Gator

[Tombstone (R.I.P.)]

Sounds like you sprayed something in that volume control that messed up the plastic parts. It's easy to do since they had to quit making the good cleaner, you have to buy something that won't harm plastic but still has a silicone lube. You have to read the label on the can carefully and test it on a pot that you don't care about. I once practically rebuilt a shortwave radio and my last step was to spray the front controls. I forget what I used but it melted the plastic in all of them so I had to replace them out of pocket, not a happy day for me!

Tombstone

[mark4]

Yes, Three watts is quite typical.
And the biggest thing to remember here is.
Were talking AVG reading on your meter.
Not Peak. You can purchase all kinds of inaccurate watt meters
that will lie like &^%.
And tell you something is there when in reality it's not.

[sixonethree]

alrighty, we're up and running again! lol I ordered a new switch from Barkett's and wired a jumper across the two black wire prongs on the switch so it's band-aided for the weekend. Now all we need is some good conditions!

[2600]

I have one more suggestion.

When the power switch goes bad, sometimes an internal part comes loose and shorts the AC power to the chassis inside the metal body of the control.

Depending on which way the prongs of the AC plug are turned, this may just blow the fuse.

Or, it may blow the guts of the switch mechanism out the back of the control.

Or, if the radio is not grounded, it can create a deadly shock hazard.

So, pulling the two black wires OFF the switch before lap-soldering them together will prevent this kind of, er, "excitement".

73

[gator7]

Very good advise 2600. That's what I did when my switch went south for the winter. Turned the radio on and off with the plug. the volume still worked. just a bad switch.


73's