VHF/UHF logper antenna

This week I finished a dualband logper antenna.

It is a design according to Gunter, DL9HCG.
Construction details can be downloaded here: https://dl9hcg.a36.de/

Logper antennas are also called LPDAs (Log Periodic Dipole Antenna).

The advantage of a logper (logaritmic periodic) antenna is its  large bandwidth combined with relative small dimensions.

I selected a 7-elements logper with following dimensions:

One starts with the construction of a dual boom

7 element logper

Measured SWRs:

430 MHz  1 : 1.4
145 MHz  1 : 1.6

First QSOs with the repeater in Goes 145.775 MHz and 438.400 MHz  PI1ZLD are promising.
http://www.pi3goe.nl

Logper pointing in the direction of the Zierikzee repeater

70 cm repeater Zierikzee

On the capital city of the island Schouwen-Duiveland a few km's south of me, the 70 cm repeater PI1ZLD in Zierikzee supports the Zeeland area.

The output frequency of the repeater is 438.400 MHz. Repeater shift is -7.6 MHz and CTCSS is 88.5 Hz. Antenna height is +55 m AGL.

The repeater used to be a DMR repeater, but has been converted to a regular 'analogue' repeater a couple of weeks ago.

St. Lievens Monstertoren

Good Es propagation on 4m

Yesterday,  good Es propagation on 70 MHz was present in the direction of Spain and Eastern Europe.

With 10 Watts from my 4 m transverter I made FT8 QSO's with HA5WA, EA6VQ, EC1A and EC1AJL.

Es propagation, May 29, 2020 @ 70 MHz

eQSL confirmation from HA5WA

50 MHz signals from India

When switching off my radio gear yesterday evening I was suprised to find a part of an FT-8 qso from India (QTH loc. JQ05) on my screen !

These were certainly the most distant 50 MHz ham radio signals I ever received:

QSO between VN4VUP and 8U8MBJ on the FT-8 screen.

What kind of propagation must this have been ? Multihop sporadic-E ?

Off topic:

Restoration PSU FP-4

With a rather simple circuit I was able to restore a Yaesu Power Supply Unit FP-4.

The PSU is almost 40 years old and the internal original circuitry was damaged. The transformer, diode bridge and 6800 uF capacitor were still ok.

I found this circuit to replace the existing electronics:

PSU circuitry

Soldered this small circuit on a vero board and installed it in the housing:

Restored PSU

Now the FP-4 PSU is up and running:

Note: PNP Power Transistor MJ2955 may be replaced by MJE2955, TIP2955 or 2N2955.

4 m transverter

With the excellent designs of Serge, UT5JCW ( http://transverters-store.com/ ) I completed a 4m transverter:

The unit operates between 70 ... 72 MHz with IF (from my FT-450) between 28 ... 30 MHz. 

RF output power is appr. 10 Watts.

Although, I do not see much activity on the 4 m band, I spotted some stations operating in MSK144 on 70.175 MHz. Maybe that is something to focus on coming days.

Circuit diagram 28 <=> 70 MHz transverter

Transverter board

Update May 6, 2020 :

Update May 24, 2020 :

First FT8 4m QSO with the transverter over 24 km with PA3EWP.

Update May 27, 2020:

Frequency counter and V/A meter incorporated:

70 cm FT-8 contest

Yesterday evening I participated in a 70 cm FT-8 contest. A good opportunity to test my 28 MHz - 432 MHz transverter.
I was able to make a couple of QSO's (PA3BGQ, PC4L, 2E0NAQ..).

eQSL from PC4L

The QSO with 2E0NAQ over a distance of almost 200 km was very interesting:

70 cm FT-8 contacts March 11, 2020

PC4L, Marcel, sent me an e-mail showing that my signal showed some frequency drift of appr. 10..50 Hz. This is certainly an anomaly that needs to be fixed.

Off topic:

Tulip field near Den Bommel