[Heath] Marauder measurements?

[Alexander N. Gerli]

Hi,

I did some further studying and I think I'm onto something here.

Checked voltages at the PA. 785V on the plate caps, close enough. 215V
screen, close enough.
-141V bias (KU) close enough. No -52V bias (KD), it remains at -141V! AHA...

So, I studied the relay on the schematic and followed the terminals back to
their origins. Pin3 returns the V18 regulator plus to ground on KD, changing
the bias to -52V, effectively enabling the 6146s. Looks like that pin on the
relay either isn't making contact with Pin2, is dirty or corroded, or
there's a mechanical problem keeping the relay tongue from throwing all the
way.

The relay was engaging gradually when I was getting my 75W into the DL. It
still engages only partially and touching the tongue makes it snap right in.
But now Pins 2 and 3 are real suspect. If the 6146s are biased off, there's
no output for sure.

I have the correct Ep on the relay amp tube V9B, 321V, so it's not like the
relay doesn't have the correct voltage to pull in.

Any thoughts?

73,

Sandy AC1Y

Alexander N. (Sandy) Gerli
'Corgi Cottage'
548 Allred Mill Road
Mount Airy, NC 27030-2202
919-625-7181

A Scotsmen walks about 900 miles each year
Scotsmen drink about 40 gallons of whisky each year
Scotsmen get about 25 miles per gallon


-----Original Message-----
From: Dave Edwards [mailto:kd2e at comcast.net] 
Sent: Tuesday, October 16, 2012 2:42 PM
To: Alexander N. Gerli
Subject: Re: Marauder measurements?

Sandy....By meter switch, do you mean a front panel wafer switch?
That and the relay you can have, but it may take a while.
I'm swamped now and through the weekend with Cub Scout and Boy Scout stuff.
....Dave


On 10/14/2012 8:09 PM, Alexander N. Gerli wrote:
> Hi, Dave,
>
> I've cleaned up the relay a bit and lubed the pivots with 
> LiquidWrench, using a pen-knife blade as an applicator. Seems to latch a
bit better now.
> Sometimes, it's gradual, sometimes it snaps right in.  Ep at V9B the 
> Relay Driver is 350.8V, so it's not a loss of voltage that's making 
> the relay sluggish. Might be mechanical.
>
>
> Now, still no output. Since the relay switches a whole host of 
> circuits, including PTT and keying the PA, I'm now suspecting the 
> relay itself as a weak link. And, after observing the Meter switch 
> wafer as it turns through its positions, I can see where the wipers 
> push the contacts apart (using a magnifying glass...). However, I 
> still think it's not as clean as it should be reliably. I've used 
> commercial contact cleaner and also wiped the wafer with 0000 steel 
> wool while turning the switch (power off!) and it looks clean, but I still
don't think I have it electrically reliable.
>
> So....what's the possibility that you could offer a Meter Switch and a 
> relay from one of your parts-cars? Compensatory compensation, of course.
>
> I think I'm on the right track, but it's sure a long haul.
>
> 73,
>
> Sandy AC1Y
>
> Alexander N. (Sandy) Gerli
> 'Corgi Cottage'
> 548 Allred Mill Road
> Mount Airy, NC 27030-2202
> 919-625-7181
>
> A Scotsmen walks about 900 miles each year Scotsmen drink about 40 
> gallons of whisky each year Scotsmen get about 25 miles per gallon
>
> -----Original Message-----
> From: Dave Edwards [mailto:kd2e at comcast.net]
> Sent: Wednesday, October 10, 2012 5:15 PM
> To: Alexander N. Gerli
> Subject: Re: Marauder measurements?
>
> typo....I meant .125!!
>
> Lemme check the third carcass Marauder. That is the one I stole the 
> power transformer out of.
> It's never coming back to life. I'll steel that resistor out of 
> there...after measuring it also.
> and I can send it to you.
> Give me 'till the weekend...not sure I can get to it tomorrow...but 
> it's yours!
> .....Dave
>
>
> On 10/10/2012 4:45 PM, Alexander N. Gerli wrote:
>> Hi,
>>
>> Well, of course, the bypass capacitance is probably the reason my DMM 
>> wouldn't settle down. But mine actually has ".125" stamped on it. I 
>> think I'll lift the end opposite the grounded one and recheck it.
>> Manual says it's a 1/2W resistor.
>>
>> Anyway, what's the possibility you could remove one from your 
>> parts-car and donate it to my radio? I'm real sure mine's way out of 
>> spec because of the pegged "plate current" (actually voltage) reading 
>> I get when choosing Plate Current on the meter switch.
>>
>> BTW, I'll be glad to send you one of my extra 1 megohm 3W resistors 
>> for your HV chain. Gotta be better than the original old 
>> carbon-composition, AND it's smaller. That one should be easy to 
>> change
> out.
>> 73,
>>
>> Sandy AC1Y
>>
>> Alexander N. (Sandy) Gerli
>> 'Corgi Cottage'
>> 548 Allred Mill Road
>> Mount Airy, NC 27030-2202
>> 919-625-7181
>>
>> A Scotsmen walks about 900 miles each year Scotsmen drink about 40 
>> gallons of whisky each year Scotsmen get about 25 miles per gallon
>>
>>
>> -----Original Message-----
>> From: Dave Edwards [mailto:kd2e at comcast.net]
>> Sent: Wednesday, October 10, 2012 4:15 PM
>> To: Alexander N. Gerli
>> Subject: Re: Marauder measurements?
>>
>> OK Sandy...I checked it on two of the old rigs plus the new one.
>> Big green looking thing....even labeled .165!
>> First, in all cases...there is some capacitance involved.
>> Starts at around .3 ohms or so, but then drops to the expected .15 or so.
>> Even after measuring all 3 of them, then going back to the first...it 
>> then goes direct to .15.  So the cap stays charged.
>> ....Dave
>> On 10/10/2012 2:32 PM, Alexander N. Gerli wrote:
>>> Hi,
>>>
>>> I measured it in-circuit right at the leads. I got a little over .5
ohms.
>>> It's on a terminal strip just to the side of one of the 6146 sockets 
>>> at the center of the chassis. You can get DMM leads in there easily 
>>> enough. Can't miss it; it looks more like an old-fashioned diode 
>>> than a resistor, no colour bands.
>>>
>>> 73,
>>>
>>> Sandy AC1Y
>>>
>>> Alexander N. (Sandy) Gerli
>>> 'Corgi Cottage'
>>> 548 Allred Mill Road
>>> Mount Airy, NC 27030-2202
>>> 919-625-7181
>>>
>>> A Scotsmen walks about 900 miles each year Scotsmen drink about 40 
>>> gallons of whisky each year Scotsmen get about 25 miles per gallon
>>>
>>>
>>> -----Original Message-----
>>> From: Dave Edwards [mailto:kd2e at comcast.net]
>>> Sent: Wednesday, October 10, 2012 2:18 PM
>>> To: Alexander N. Gerli
>>> Subject: Re: Marauder measurements?
>>>
>>> Didn't check it yet Sandy....can you tell me if you measured it in 
>>> or out of circuit?
>>> ...Where is it located, so I don't have to bust open the manual.
>>> .....Dave
>>>
>>>
>>>
>>> On 10/10/2012 2:12 PM, Alexander N. Gerli wrote:
>>>> Hi, Dave,
>>>>
>>>> Had a chance to check that .125 ohm critter yet? I just received a 
>>>> couple
>>> of
>>>> resistors from Newark to change out the 1 megohm 2W in the plate 
>>>> voltage metering line (have a 3W job going in there and I bought 5 
>>>> of those for spares). And for the 6.5K ohm 7W in the LV chain, I 
>>>> have a 6.8k/10W for a substitute. Couldn't locate a 6.5K anywhere, 
>>>> so I got as
>> close as I could.
>>>> And, wouldn't you know, a feller on eBay has some .125 ohm/10W 
>>>> ceramic 'sand' resistors on the cheap, so I got a pack of 10! Now, 
>>>> it might be impossible to cram that 10 watter in there where the 
>>>> original one was, but for the price you can bet I'm going to try, 
>>>> HIHI. Should have those by Friday. Who knows, just might work...
>>>>
>>>> 73,
>>>>
>>>> Sandy AC1Y
>>>>
>>>> Alexander N. (Sandy) Gerli
>>>> 'Corgi Cottage'
>>>> 548 Allred Mill Road
>>>> Mount Airy, NC 27030-2202
>>>> 919-625-7181
>>>>
>>>> A Scotsmen walks about 900 miles each year Scotsmen drink about 40 
>>>> gallons of whisky each year Scotsmen get about 25 miles per gallon
>>>>
>>>>
>>>>
>