[ARC5] IF transformers.

[Brian Clarke]

Hello all,

Mechanically, all that you say is correct. And any Tech O in the last 70 
years could have changed the base mounting plate around and daubed the 
correct red paint. I have found my daughter's red nail varnish does an 
excellent job.

Electrically, there is a difference between the third IFT and the other 
two - all the coils are the same, except that the third has been tapped down 
to give different input and output impedances, while still maintaining the 
same trimmer capacitors as in the other two IFTs. To tell whether you have a 
third IF transformer, you will need to check that the outer connections go 
to the trimmer, and a tapped wire, not connected to any internal capacitor 
goes to the base connector.

So, Ken, if it really was a third IFT and you want to use it as a first, you 
need to change the internal connections to match your second IFT, ie, base 
connections across the whole coil for primary and secondary.

73 de Brian, VK2GCE.

On Sunday, June 16, 2013 9:28 AM, you said:.


> On 15 Jun 2013 at 18:04, WA5CAB at cs.com wrote:
>
>> We know that a PO had the
>> cover off (and reinstalled it backwards) because if you just remove the 
>> mounting bracket and
>> rotate it 180 deg. so that you can plug the thing into the 1st IF 
>> position with the tube cover on, the
>> dot would still be toward the front.
>
> You are absolutely correct: that is exactly what happened, but it wasn't a 
> PO. It was,
> apparently, the factory. The cover was on the can 180 degress around. The 
> red line on the
> bottom of the cover was on the side opposite the red line on the base. 
> They should have
> been on the same side.
>
> The screws were very difficult to remove as the original red locking-paint 
> was still there.
>
> I was (again) surprised.
>
> This is the very first "ARC-5" receiver I have ever seen which had two 
> factory assembly
> errors.
>
> Ken W7EKB