[Boatanchors] HRO Alignment of Plug-In Coilsets

[Bob Young]

I plug the coil sets in and out, adjust the inductance while out and plug it back in again. I do this until I find the point where the sensitivity is greatest. It's a PITA but eventually you get the hang of it and they are not real touchy anyway. The trimmers can be accessed on HRO-50's and 60's while plugged in don't know about the older ones but I believe I have read somewhere that there was a method. The trimmers are very precise, the coils aren't. I do the trimmers first to get it on frequency.

Bob Young
KB1OKL


> Message: 3
> Date: Tue, 13 Jan 2009 21:09:54 -0500
> From: "Olaf Madsen" 
> Subject: [Boatanchors] Fw: HRO Alignment of Plug-In Coilsets
> To: 
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> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> 	reply-type=response
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> 
>  From: "Olaf Madsen" 
> To: 
> Sent: Tuesday, January 13, 2009 9:05 PM
> Subject: HRO Alignment of Plug-In Coilsets
> 
> 
>>I am working on an HRO-7,trying to make the alignment on the various 
>>plug-in coilsets.----HRO-5,or any of the other HRO's also use these 
>>coilsets.
>>
>> The sensitivity varies greatly over the tuning range,particularly for the 
>> General Coverage Ranges (say 3.5 to 7.3 Mc for the ''C'' set )
>>
>> The procedure for alignment described in the instruction manual allows for 
>> adjustment at a HIGH frequency point of the range (7.3Mc for the ''C'' 
>> set ) by the trimmers which are accessable at the front of the coilsets 
>> from the inside of the receiver.
>>
>> Any alignment to the LOW frequency end must be made by changing the 
>> Inductance of the coils from the back of the coilset---however---there is 
>> NO ACCESS to them ,except when the coilset is OUT of the receiver..---the 
>> same goes for the Padding trimmers,they cannot be reached while the coil 
>> set is plugged in.
>>
>> In the words of the manual : ''The original alingment was ("is'') 
>> accomplished by the use of precision,crystal -controlled test 
>> oscillators.---No realignment should be attempted,'' etc etc.
>>
>> What's  a ''boanchor ham'' to do with a 50 odd year piece of gear that 
>> needs some TLC.--What do you say you old  guys from ''National 
>> Company''---Any advice ????---or references.
>>
>> Tnx fr any help --73 de Olaf,KF4TP---
>> 
> 
> 
> 
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