[ARC5] ARC-5 Alignment Question

[J. Forster]

I'm not worried. Just curious. You have to respect those design engineers.

Thanks,

-John

================


> On 20 Dec 2010 at 15:19, J. Forster wrote:
>
>> The ARC-5s often use metal tubes. Are the inter-electrode capacitance
>> variations of such tubes significantly better than glass tubes?
>
> No. They are supposed to be identical, although there is, of course, some
> very minor variations between any two tubes.
>
> The main reason for metal vs glass tubes in those receivers (IMHO) is
> shielding. The metal tubes are shielded better. There MAY also be an issue
> with "delicate-ness" in that the metal tubes are (obviously) less likely
> to get
> broken.
>
> However, I have had at least a couple of ostensibly NIB ARC-5 receivers
> which had at least one glass tube in them. Furthermore, I know that the
> top
> cover often has -G or -GT versions of some of the tubes painted on its
> surface as being suitable replacements.
>
>> Are either metal or glass tube characteristics sufficiently well
>> controlled so that a receiver could be fitted with off-the-shelf tubes
>> and perform w/in specs without alignment, after initial alignment?
>
> Absolutely, as long as you don't use some weirdo off-brand unknown POS.
>
> The Mil-spec tubes are all OK, IMHO.
>
> Mike will correct me if I am off here. ;-)
>
> I think you are worrying needlessly. Just put a set of good tubes in it,
> align to
> frequency, and use it.
>
> Ken Gordon W7EKB
>
>