What a nice watch! Yours is not a transitional model, if anything, it's an early model. The first Cal. 420s were the "Prime" models but after a while, Zenith decided to rename that movement the "El Primero HW". When they replaced the machinery for the movement around the year 2000, the made some minor changes and added the "Z". Since yours lacks one, it must be a late 1990s model.

Hartmut Richter

 

Thank you very much for the reply! I'm much more relieved.

I discovered something else that assured my mind.

I was browsing a thread created by sempervivens about this caliber and found a page of a catalogue showing the movement "El Primero HW" next to a picture of said movement in which the caliber's number does not have de "Z". So you're right it must an early piece.

Thank you!

 

Gorgeous movement!

Wear your Zenith in good health!

 

Re: Doubts about my Zenith El Primero HW ref 01.500.420

Congratulations on your Zenith El Primero HW!

I understand your worries whether everything is all right. If you read that thread with the overview of Zenith cal 420 'Prime' and 'El Primero HW' (which I wrote 8 years ago), it clearly suggests that the Zenith Prime was made with cal 420 and the Zenith El Primero HW was only available from 2000 onwards with cal 420 Z.

But it is not that simple. The fact is that the first batch of the El Primero HW were already available ca. 1998: a year before the introduction of cal 420 Z.

The reason why I didn't know this eight years ago, is the fact that the El Primero HW was not featured in the 1998 catalog. In fact you won't even find it in the 1999 catalog.

But in reality the El Primero HW watches must have been available from 1998 onwards: because that is when the automatic version with the same design was introduced (ref. 01/02.500.400).

Also you can deduct it from the fact that the name "El Primero H W" for the first time appears in the catalog for 1998.

As you have observed:

some have the caliber 420 and the "z" engraved inside a rectangle, others seem to have the "z" added next to the caliber number and others don't have the "z" engraved at all (like mine and others I've seen).

The first batch of the El Primero HW (ref 01/02.500.420), which was for sale in 1998, used cal. 420.

The second batch, in 1999, was a transitional model: it used cal 420 Z, but for the bridge Zenith must have used up the remaining stock of bridges of the older cal 420 and simply added a 'Z' on the bridge.

Finally and probably from ca. 2000 onwards Zenith also had new bridges with the full cal '420 Z' designation inside a rectangle.

Since there is this difference, you can tell that yours was one of the first made of this model, available in shops in 1998.

Enjoy it and wear it in good health. b-)

 

Thank you very much for your responses guys! I'm much more relieved now!

Now I can't wait for it to arrive. When it does I'll post more pictures!

HAGWE!

 

Well guys it's here!! Absolutely love it!

HAGW!

 

Congratulations! Although I still prefer the automatic version.....!

Hartmut Richter

 

Hi! Nice watch and great explanation, I have a question. I have almost the same watch but mine has the 420 inside the rectangle, and the Z outside. So it must be from 1999. Since this one was made only in 1999. Does it make it more desirable or collectible or not?

 

Welcome to Watchuseek. The "Z" was a standard addition in those days to distinguish the older generation EPs from the newer generation (slight amendments in the escape gear and lever) and is itself nothing special. Only if you have a rare run with an aesthetic fauult (e.g. Zenith World Time watch with "Hawai" instead of "Hawaii") might you expect that to rise in value. It is all down to whether people are willing to pay the extra - and frequently they are not. If it was a functional fault, then it's a dead cert that you won't get additional $$$ for it, of course!

Hartmut Richter