Application Note No. 41-010511, Rev 2
2
Printed in US
Release Date: 08-2014
O M L
Inc.
300 Digital Drive Morgan Hill, CA USA 95037 Tel: 408-779-2698 Fax: 408-778-0491 www.omlinc.com
Figure 1 – 85105A Interface Adapter near front panel
Keysight designed a front panel adapter, the 85105A Interface Adapter, P/N 85105-60015 (see
figure 1), to allow the use of the earlier 85104A Millimeter Wave Test Set with the 85105A. The
85104A Test Set utilized a group of discrete waveguide components and an 8355xA Millimeter
Source Module (Armadillo) configured as a millimeter wave VNA test set. This Interface
Adapter broke out the I.F. interfaces to BNCs (f) and brought the DC bias voltages out to another
special Sub D connector.
Figure 2 – Narda power divider in the 2 to 18 GHz range
OML has engineered modifications to the 85105A which allow it to be used with both the
Keysight products and with the OMLMM. One simple modification is necessary to the internals
of the 85105A. The 2 to 8 GHz power divider must be replaced a unit capable of operation to 20
GHz. The Narda Model # 4456-2 (see figure 2) is a 2 to 18 GHz power divider that is widely
available from used test equipment vendors for $200 to $300. It is still available new from Narda
L3COM for less than $700. It is a "drop-in" replacement for the 2 to 8 GHz Narda unit supplied
in the 85105A (see figure 3) and has the same dimensions although the mounting hole pattern
may need slight modification. It has been repeatedly tested by OML and found to have very little
degradation between 18 and 20 GHz. Click here for (4x-xxxxxx_85105A) on replacing the
85105A L.O. splitter.