The small powerpole housings use separate housings for each contact, and are typically found in red and black,
but you can use other colors such as yellow or green. The housings have dovetails on all four sides, two male
and two female, that you use to mate the two contact housings together. This allows you to rotate the housing
90 degrees, which can be used for unique keying. Unlike the SB50 and larger dual-contact housings, these are
not keyed by color so if you want to key them you have to change orientation of one of the housings instead.
Remember to buy extra black housings so you don't deplete your black housings from existing red/black sets.
The housing is compatible with the PP15 and PP30 silver-plated copper solderable contacts, as well as the PP45
tin-plated copper crimp contacts, although the current ratings are different for the three. You should be
able to mix the contacts, and for example connect a PP15 end to a PP30 end, or a PP30 end to a P45 end without
having any problems with the contacts. Considering the small cost difference between PP15 and PP30, there's
really no reason to bother with the PP15 contacts.
There are several larger housing available also, which use contacts found normally with the SB50 and larger
housings, although these are pretty rare to see.
In addition to larger housings, you can also "stack" housings in parallel, increasing their current handling
capacity, or increasing the number of different kinds of contacts. You could mate a yellow on the other side
of the black for example, giving you a ground, +12, and a +5 line.
You can easily pay $2 a set for powerpoles at a hamfest. Buy them in bulk online if you can - get together
with friends that need them also so you can get a better price with a higher quantity purchase. Just over $1
per set is a good price. Not everyone includes the drift pin for locking the + and - housings together.
Although generic housings are widely available on eBay and Amazon, the quality of the generics is a problem.
By far the most common issue is the dovetails having a poor tolerance, and either fitting loosely together,
or being difficult (or impossible) to mate together. Tought fits are often very difficult to separate, and
loose fittings often pop apart from just the force of inserting a locking pin. Get your small housings from
a known reputable seller.
