[Hammarlund] HQ 180 coil rewinding

[Bob Camp]

Hi

If it’s stranded, it’s Litz. 

You are going to need several numbers:

1) The size of each wire in the set
2) The number of wires in the set
3) A guess at the insulation material
4) The number of turns in the coil
5) The winding style of the coil
6) The dimensions of the finished coil
7) The primary to secondary spacing (if applicable).

So, the likelihood of getting all that right is pretty remote. What happens if you get it wrong?

a) Inductance is off a bit, you re-tune.
b) Q is off a bit, your RF selectivity isn’t what it was (could be better).
c) Primary secondary stuff is off a bit, your gain (and noise figure) are off a little. When was the last time 40 meters was dead ? 

The real fun with Litz is that you simply can’t get the stuff. Yes I have a spool, but it’s what you would use at 50 KHz. There are dozens and dozens of combinations. If you call up your wire guy, the first question is how you want your 500 lb minimum order shipped. Let’s see, at $10 a pound that’s …. 

Do it up with what ever you have and you can enjoy the radio. 

Bob

On Jul 24, 2014, at 10:09 PM, Robert Sauvan <rsauvan at beyondbb.com> wrote:

> Well,
> I guess I cant say for certain if it is Litz. Someone suggested it to me that it is Litz. It is definitely a stranded wire. Very small. All of the Litz wire I have seen is covered with a cloth but this coil wire is not. It looks like enameled wire without any other covering but it is stranded. I am having no problem counting the turns and I can verify them while unwinding the old wire if it doesnt come off in pieces. I dont have a real good micrometer but I will see what I find and I do have some old ARRL handbooks that my have the needed wire no. info as well. This radio being as broadbanded as it is may not be super critical as the number of turns as long as Im pretty close but Im sure the number of turns isnt going to be a problem since I am able to count them now.
> 
> Thanks-Bob-W0YBS
> 
> 
> 
> On 7/24/2014 7:29 PM, Al Parker wrote:
>> Hi Bob,
>>    Is it Litz wire?  I haven't had the "pleasure" of having to get into rewinding those coils, but thought Litz was used on lower freq. stuff. If it's not Litz, just get an end of what's there, and measure it with a micrometer, if you have one.  Then go to a wire table in an old handbook to see what no. it is.  The actual wire size is not critical, the number of turns is, somewhat.  Be glad it's not the 80m coil ;-)
>> 73,
>> 
>> Al, W8UT
>> www.boatanchors.org
>> www.hammarlund.info
>> 
>> "There is nothing -- absolutely nothing -- half so much
>> worth doing as simply messing about in boats"
>> Ratty, to Mole
>> 
>> On 7/24/2014 8:00 PM, Robert Sauvan wrote:
>>> Hi all,
>>> I have a 180 that has a burned 40 meter antenna tuning coil T-15. I have
>>> tried to find a replacement with no luck at all. So, I have decided to
>>> rewind it myself which really doesnt look to be all that difficult. My
>>> question though is what size Litz wire should I use? The primary winding
>>> is good and the wire size looks to be much larger than the secondary
>>> winding wire. Anyone have any idea what I should be looking to pick up?
>>> 
>>> Thanks-Bob-W0YBS:
>> .
>> 
> 
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