>Can someone give me some info on this amp. Duty cycle,
High duty-cycle, thanks to it's resonant-choke filter supply. For RTTY,
AM, or FM broadcasting, the resonant-choke filter is the best.
>power out with 100
>watts drive.
The power gain is roughly x 13 with reasonable drive.
>How does it compare to my TL-922A.
The biggest difference is obviously no 160m on the Henry and about 100
pounds. The 922 sometimes oscillates at 130MHz, the Henry sometimes
oscillates at 95MHz. Both use beautiful, surprisingly-similar
silver-strap VHF "suppressors". The Henry T/R relay is an impressive
11db louder than the 922's stentorian T/R relay.
>Are the 3-400 tubes
>similar or interchangeable with 3-500s?
Semi-Yes. 3-500Zs are taller, so they are usually not mechanically
interchangeable with 3-400Zs unless one does a bit of hammering on the
sheet metal. Another solution is to use a custom flat anode cooler.
- The peak emission in a 3-500Z is the Same as a 3-400Z's because they
use the same 5v 14a filament. Thus, there is no difference in PEP.
OTOH, 3-400Zs have slightly more Mu than Eimac 3-500Zs, so they need
fewer watts to drive to their maximum PEP capability. Since Eimac is out
of the glass tube business, my vote for the best replacement would be the
Amperex 8163/3-400Z . I use a pair in my SB-220. One was manufactured
in 1967. Power out is about 1400 w pep.
If I owned a stock Henry 2K I would:
1. Install a step-start circuit.
2. Install high speed switching so that the amplifier would not
hot-switch with modern radios. {January, 1994 *QST*}
3. Install lower VHF-Rp parasitic oscillation suppressors.
4. Remove the inane 7.5 ohm resistor and overload relay in the hv
negative return, and install two 10w, 10 ohm glass-coated resistors in
series with the lead to the HV-RFC.
5. Add 200 peak ampere rated diodes across the meter movements.
6. Add a VHF attenuator-rated ferrite bead at the top of the HV-RFC.
7. Install a 120v/6.5kA-rated MOV across one of primary windings on the
HV.
transformer.
8. Pot the resonant-choke in polyester laminating resin. (note: this
is a lot easier than it sounds. See http://www.vcnet.com/measures for
information on how to. )
Rich---
R. L. Measures, 805-386-3734, AG6K
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|